as far as flavor vs essential oils go...they are just what the names imply...flavor oils are just flavored, cosmetic grade oils, and essential oils are the same essential oils you hear people talk about. some EO's that people use are peppermint, spearmint, sweet orange, tangerine, some use tea tree as a healing lip balm. tha flavor oils are endless...grape, strawberry, bubble gum, peach, vanilla, cappuccino, cucumber melon, buttercream...those are a few that i have. manly flavors could be vanilla, my hubby likes grape, some may like the mints or you could just not put pany in and just have it be "unscented".
i don't use special eqipment. i make a double boiler type thing with my pytrex measuring cup and a pan of water. for clean up i just always eveything off as i finish with it. it's harder to clean up is youlet things solidify. by using the pryrex cup it makes it way easier to pour lip balm into the tubes.