It is not how good you are at poker that determines how much you make, it is how much better you are than the people you play with, so finding poor players to play against is almost as important as being a good player.
The process of locating the most profitable of the currently available tables/tournaments starts with choosing the right poker network. There are many factors to take into consideration when choosing a poker network, but the two most important factors, which dwarf the other ones, are traffic and ease of the competition. Find out which networks have enough traffic in the type of game you play, so that you don’t have to spend a lot of time waiting for players to play with, then choose the one with the softest competition.
For example, Titan Poker has a lot of traffic, but not always the easiest competition. Pacific Poker has incredibly easy competition, but not always much traffic. One site with a very nice blend of somewhat easy competition coupled with a lot of traffic is Party Poker.
If there is a huge difference in traffic, and just a small difference in softness, between some of the alternatives, it might be better to go with the one with the highest traffic. But usually softness rules the land.
Something many players forget is that the ease of competition also changes during the day. At peak traffic hours the competition is easier than at the lowest traffic hours. This is due to the fact that many sharks don’t have jobs or schools to go to, and tend to play whenever they feel like it. Many of them wake up very late and go to bed very late. Fish on the other hand, live their 9 to 5 lives and only have time to play in the evening. This mass entry of fish in the evening drives the traffic upwards. Since the number of sharks don’t increase by as high of a percentage in the evening, this results in a better fish to shark-ratio which means easier games. Weekend afternoons are typically soft too for the same reason.
Be aware that poker is played all around that world, so networks dominated by Europeans will have different peak hours than “American” networks. You can check out how the traffic on your preferred poker network developed the last 24 hours on Poker Scout.
When you have chosen the network and time of the day, you have to choose which table/tournament to join on this network. For cash-games, you have to look at the statistics in the lobby. Bad players are typically loose, so tables showing a high average percentage of people seeing the flop are typically easier to beat. Be aware, though, that the fewer people there are around the table, the more hands you should play. So a table with say 9 players with a 30% figure, has worse players than a table of say 6 players with the same figure.
Not all networks show this figure in the lobby. On these sites you have to open some or all of the tables and see for yourself which table seems most desirable. There are other statistics in the lobby of course, but they aren’t as useful in finding games as the “percentage of players seeing the flop” statistic.
Many think big pot-sizes, which are also shown in the lobby, are a sign of poor players because poor players often call when they should have folded, and this may be the case. But poor players also often call/check when they should have bet/raised. That being said, big pots are more often than not a sign of poor players, it is just a much less reliable sign than flop-percentages.
When you have joined a table, but later find out that it is not soft, or it became harder due to poor players leaving and better players joining, then Run Forrest, Run! to another table.
Tournaments are trickier to game-select because there are no statistics in the lobby to look at, and once the tournament starts, you are stuck with whatever players are in it. There are, however, statistics elsewhere for Single-Table Tournaments. On a site called Sharkscope you can type in the ID number of the tournament you consider joining, and it will show how well/poorly the players who have already joined the tournament have done it in previous STTs. Be aware that some poker networks don’t allow you to use Sharkscope.