Part of newbies getting chain tattoos is the whole leg position thing, another part is that newbies have dirty drivetrains. I can grab my chain and only will have a light grey mark on my hand. Although I also owe a lot to Rock'n'Roll absolute dry lube. Absolute dry is self cleaning and repels dirt well.
Wipe the chain before every ride with a paper towel or rag. Lube every 100-300 miles or so. Use a chain cleaner when necessary and don't forget to clean the rear cogs. I use credit cards that I get in the mail from companies wanting me to sign up, wrap a paper towel around it, and pedal while placing it between each cog. Also clean the derailleur cogs and front chainring. Do this and even if you do get a mark on your leg, it will be so faint you will barely notice.