Try getting Chemist's Own Pain Tablets, they dissolve real quick, easy to filter (I use a shirt) and they are dirt cheap (usually).
One pack = 240mg, gets me relaxed, two packs = 480mg and will get me buzzing pretty good.
I love the codeine, I usually use grapefruit juice to help make it last longer, and recently have been using St. John's Wort and alcohol to help boost it a bit.