Honestly I am not so sure there are too many ways to avoid getting burns when welding, especially if its just a hobby for you. I'm sure the pros that weld all the time went through a period where they got burned frequently before they learned not to touch unprotected metal.
I know you mentioned you were using MIG on Aluminum. I have never welded Aluminum before, but will be learning soon. BUT you might take a look at going to Tig for most of your welding. I started learning to Mig Jan/Feb of this year. I started with Flux Core Wire Feed, then wend to CO2 Shielded solid fillers. (I used CO2 because I have a Kegerator, and I had a couple spare bottles of CO2). Anyway, with Mig I always had tons of splatter, and since starting with Mig I have been burned more by spatter than probably my entire life before Mig. Several times I considered giving up on learning Mig and tossing the thing into the trash. BUT I knew I needed to weld Aluminum at some point. Mig was a stepping stone for me though because I wanted to weld Stainless and Aluminum in the long run, and Mig was a cheap way to practice with electric welding.
I had the need for welding Stainless and Aluminum come up a little faster than I expected. I started watching videos online to pick up some tips on what equipment to buy and how to go about learning Tig. One thing I noticed in the videos was that there seemed to be absolutely no splatter. It also looked like you had 10 fold the control over the weld, and the final product looked a million times better than Mig, and even better than Oxy.
Couple weeks ago I bought a "cheap" Tig welder from a friend who bought it and never opened the box. I say "cheap" because I paid $400 for the welder (Lotus Tig200 200amp AC/DC). I put it in quotes because that $400 purchase cost me close to $1000 before I ever put a single bead down. Trust me before I put that first bead down I was having major buyers remorse, and asking myself WHY I was spending so much. (and in reality I really got off cheap in comparison because of my friend).
Anyway, what I am getting at is that so far in the 2 weeks (probably 30-40 combined inches of bead), I have not had a single splatter, or molten metal dripping etc. I still have the brain farts and grab hot metal with bare hands, and the last time in the shop I was leaning over a project trying to get a better view and rested my stomach on the end of a hot filler rod. But as for all the burns I was getting from Mig, I don't even see how I could get those burns with Tig. OH and to add to that, even my very first weld with Tig was 10 times better than my best ever weld with Mig. I've already taken the Mig welder off my welding cart and put it and it's supplies on a shelf where I hope never to see it again. I'll probably only hold onto it because it's easier to take that machine and flux core wire to my deer lease than it is to deal with all the stuff for Tig.
Until recently I never wore gloves or even welding glasses for Oxy/Ace. Just a pair of Oakley sun glasses for my eyes, and if I wasn't to hot a cotton t-shirt. Shorts or jeans made little difference. I've never gotten any really severe burns (meaning big burns sending me to the hospital), but my fingers have seen blisters countless times since age 14, tops of my feet an occasional burn. Chest and Arms occasional splash burns too.
I started learning to weld with Mig and Tig over the past 3 or 4 months, and I did make some changes. I won't touch a torch without gloves if the power supply is plugged into the wall. Don't care if the power is off or on. I started with the cheap bulky leather gloves from Harbor Freight, but 2 weeks ago when I bought my Tig welder I also bought a pair of Iron Flex Tig Gloves so I could have better feel/control of the torch. All I can say is night and day between cheap gloves and these gloves.
When I started Mig I bought a cheap auto darkening Harbor Freight helmet (10 shade max), and I really liked it in comparison to the fixed shade goggles that I was taught with. Again when I started Tig I was told I should look at a helmet that could darken to at least as 12 shade. I didn't buy top of the line, but I spent $120 on the helmet and on the drive home I was wondering if I had just been conned into something I didn't need. And again I was shocked by the helmet too. Even though I haven't used anything darker than a 10 so far, the visibility through this things is again night and day.
I've also added a cheap leather apron, but I probably wear it 50% of the time, but as soon as I solve the summer heat issues in my Garage I intend on wearing it more. I won't weld with anything with shorts anymore, either I wear jeans, of (don't laugh) Chef's Pants. I took a couple of culinary classes where I needed them, and they are comfortable to wear in the heat, and so far been loose enough that my legs haven't been burned, but not loose enough to be a safety issue.
I'm still wearing tennis shoes most of the time in the shop. I have a couple of pairs of leather boots (Harley riding boots, and Harley work boots) and honestly they both gave me a false sense of safety, and I have burned the tops of my feet in both of these boots while using the plasma cutter. I'm thinking about cutting one of the leather aprons and making leggings to see if that works better for me.
I don't have a welding jacket, and I rarely ever work in my shop with long sleeve shirts or jackets. Working on the farm as a kid I had more accidents where long sleeves snagged something, so I am still a little paranoid of anything on my arms. I fortunately I never lost any appendages in those accidents. But it's more an act of God that I didn't loose anything than I care to risk these days.
I guess to sum up this long book of a reply. I have always assumed that burns were just a part of welding, and expect them to happen. I keep basic first aid kits for burns, and just make sure I know where they are and how to treat the burns with them. These days though I am taking steps to minimize them where practical. If a $5 apron from Harbor Freight will keep that hot filler rod from burning my stomach (happed just last weekend when I didn't use the apron), then I'm going to wear it. I no longer consider gloves optional with any form of welding or plasma cutting. While I might still probably occasionally use just my Oakleys with Oxy/Ace, it won't be frequent, and in time I will retrain myself to never without the helmet.
But at age 44, I have come to appreciate having the use of all my appendages. I have learned that I am not immortal, and can't live through everything. And probably most of all I have learned to appreciate the years I have had, and to work towards making sure I have as many more years as possible.
I know accidents are a part of life, but as I get older I don't recover from them quite as fast as I used to so now instead of just letting them happen I try to think ahead enough to try to at least keep the injuries from those accidents to a minimum. And for some reason these days, the same injuries seem to hurt FAR FAR FAR more than they did 20 years ago...
OH, one other thing I have learned over the past few years. Some times it is true that "you get what you pay for." I usually go cheap with tools, especially when I am buying them specifically for a given project and may never use them again. Just this past year I have regularly been shown how much better good quality tools get the job done. Going forward I will lean more towards the best quality I can afford when I need something rather than going as cheap as possible just to get the job done.
