go as quickly or as slowly as you want to its your friggen ink. the only ting i will tell you, though, is at 18 and 19 you really need to be sure you're getting things you'll want forever. i have a friend who finished his full sleeves by 20, and he's bummed, to be honest. he's got so many more life experiences and better ideas to draw from now, he really wishes he hadnt gotten those matching celtic half sleeves on each arm, cause they really dont match the full-color old school style he finished his sleeves with LOL. they're still cool, he still likes em, but they could be SO much better, ya know? ive been getting tattooed slowly and steadily since my 18th b-day (im 25 now), and all ive gotten so far is one sleeve, two tats across the back of my shoulders, and my very first one, a small one on my leg i regret getting so small, and on my leg, everyday. all im sayin is for me, pacing myself has worked. by 30 ill have done my chest, and i figure im saving the rest of my back for my 30s so i have something to do (since i dont think im going to tattoo my other arm, i like the one sleeve look) and do a leg in my 40s. i figure by then ill be sick of the pain of getting Fn needles Fn poking the hell out of my Fn skin. anyway, all that to say, find a pace that works for you, and fuck everyone else.