Mug choices
1000 4, 5 or 6 piece: Stein, chalice
1500 4 piece: Stein, horn
1500 5 piece: Stein, chalice
1500 6 piece: Stein
2000 4 piece: Horn, Stein
2000 5 piece: Stein
2000 6 piece: Goblet, pitcher/Stein
2500 4 piece: Horn
2500 5 piece: Goblet, Stein/Horn
2500 6 piece: Tankard, Goblet
3000 4 piece: Horn, tankard
3000 5 piece: pitcher, goblet, horn
3000 6 piece: pitcher

Source, Tzz
General rules
Drinking is all about board control. Here are a few simple rules to help you control the board. They aren't things that work 100% of the time, but are great general guidelines.
1. Play the highest piece whenever possible, on an opponents stein whenever possible.
2. Don't finish a row worth 100, unless its split 3 pieces each.
3. Let your opponents finish rows of 6-7 of their color in the early game.
4. Don't finish a 6-7 color row in the early game, unless its with a barrel.
5. If your opponent ever has 4 out of 6 colors in a row, try to block the 7th spot, with a piece of a different shape and color next to the 7th spot. Blocking is also useful for most of your opponents rows in the late game as well.
Source, Tzz
General rules
4 color drinking with horns
1. If You're using a horn, Clear every row you can.
2. If your not using a your but your opponent is, clear every unblocked row.
Classic Drinking
Read the rules and keep a count of how many stains you have compared to your opponent. Whoever gets the end bonus usually wins. Also, remember that every stain you have is 20 points for you AND 20 points you opponent cant get. So don't be afraid to win the ending bonus by a lot. many times its actually helpful to avoid clearing 100 points rows with your pieces or intentionally clearing an opponents 100 point row. The bonuses you get from staining their row after you clear it, balance out the 100 points they got, and you get the 200 point endgame bonus as well as board control.
Source, Tzz