The best hand in 2-7 is 23457. A is
high, not low. Flushes, straights and pairs are bad. It is NOT like razz even though it's lowball.
You play
triple draw like any other game but maybe tighter. Hold on to any starting hand with four cards 8 or under. An 8hi will often win. You have 3 draws to make your hand. Once you have it, raise. Never hold on to a hand that needs more than one card. Do not stay pat on anything higher than 9 hi in triple draw, unless it's the final draw and the other player(s) are still drawing. That's where position is helpful. It's good to be the last to act.
You can tell the good players from the bad by whether they regularly draw 2 cards or more (if not in an unraised pot.) Lots of people who haven't played it much think that 3 draws will be great. It's not. It's hard to get the card you need. So you want to keep the pot small -- until you have a whole hand.
If you have an 8 hi or 9 hi and someone keeps raising you, they may well have you beat. In 2-7 TD, people somehow seem to make a lot more 7 hi
hands. You
will see a 23457 vs. 24567 on occasion. It's painful.
In triple draw betting speeds up as people make their hands. Bluffs are usually pointless. Someone is likely to call that last bet.
In
2-7 Single Draw, a 9 hi or 10 hi will often win, and it's relatively safe to stay pat on a J hi --when others are drawing. (Do not bet all that much, though.) Again, position helps. In Single draw, it's rare to see a 7 hi or 8 hi. It's the game equivalent of a boat. A showdown between two 7hi hands is vanishingly rare in single draw.
In single draw (which is NL), it's best to get your raise in preflop, because so often the other guy will catch badly on his draw and will not be paying you later. On those rare occasions when both players catch a good hand, the bets can get big after the draw. But normally, it's a pretty mild-mannered game if the players are savvy. A 3x bring-in bet will keep others in the hand when you have a good pat hand. Much bigger, and they won't call.
bluffing is more possible in single draw than in triple draw. Use this sparingly.
That's these games in a nutshell. It is, like any form of poker, more complex.
It's not at all a game of chance alone. Both of these games are fun and interesting -- and skill is needed.