How to Play 5 Card Draw
In 5 card draw each player is dealt 5 cards. No surprise there then.
There is then a round of betting based on these 5 cards.
You then change as many of the 5 cards as you wish. Eg you choose to change 3. You hand these 3 (face down) back to the dealer and then you are dealt a different 3 cards from the top of the deck.
You wouldnt really want to do any pre-flop betting here. Keep the 99, change 3 cards....you are given 5,6,9.
Your hand is now 9,9,9,5,6 ie trip 9's
Now comes another round of betting.
With trip 9's a little bet is certainly worthwhile.
Best hand wins the pot.
Looking to draw inside straights is not really a good idea. Keeping individual high cards is also not a good idea. eg with the example above, keeping 9,9,A and swapping 2 cards is not a good idea.
The best general strategy is to work from your pairs, and draw from there.
Keep an eye on how many cards people change.
Standing Pat (changing no cards) may indicate a made hand, often a straight. This obviously can also be done as a very confident bluff. If bluffing naturally you should be betting this hand accordingly.
Changing 1 card may indicate 2 pair, or a flush or straight draw. If they back off any betting post-draw it is likely they missed a flush or straight.
Changing 2 cards may indicate trips, or possiple a very weak draw.
Changing 3 cards almost without fail will indicate a pair. Obviously they can have no higher than a pair, so that is good information.
AA sometimes worth a bet, especially if checked to you in late position.
2 pair hands are worth a bet, especially if one of the pairs is a high pair.
Trips are certainly worth a bet.
Generally trips upwards are good here. Obviously take into account your opponents play. IE if they have been playing very tight, change 1 card, and then come out raising like a crazy horse, then it is probably safe to assume trips are no good.