i never follow recipe. mainly because i can't read, but during my chef days, i was taught how to taste food first before i learned how to cook. so naturally, i cook with by tasting, not by the book (makes your cooking more flexible that way when the number of portions you are cooking varies). i just taste it and see what's missing and add whatever's needed accordingly - that's probably why i "rawr" at baking, since you can't fix it once you pop it in the oven.
for bulgogi, it's just soy sauce, sugar, sesame oil, chopped garlic, gingseng, and onion (and whatever other veggies you want). with soy sauce and sugar, it's about 2:1 OR 3:1 ratio (start with just enough soy sauce to cover the meat, mix with sugar, cook couple pieces and see how it tastes). sometimes, i just use store bought teriyaki sauce and add little more soysauce to it. sesame oil is the tricky part. with the right amount, it tastes good, but if you go little bit overboard, it can ruin the whole thing. then you have to add more meat and soysauce to kill sesame oil. for gingseng and sesame oil, you want it about half of the sugar amount, but i would start with less and see how you like it first. and, of course, little bit of salt and pepper.
as for meat, i find it easier to slice when it's just little bit thawed (when it's frozen enough so that it can remain still while you add pressure with your knife, but thawed enough so you can actually slice it). you want the meat to be thin, about 2-4mm.
