I have played with a lot of sites and tried to take advantage of deposit bonuses. I think the first thing you should look at is:
(points required for completion) divided by (number of days until expiration -1) to find what you need to earn in terms of points each day. Don't change the way you play or the stakes you play (unless of course your BR changes enough). What you should be looking at is playing more tables and playing more hours. If you cannot really alter these things, then maybe play different games.
If you are playing SNGs or scheduled tournaments then these aren't going to earn you enough points per hour. Cash tables, IMO, are the only way to play through deposit bonuses, unless your BR is larger than the bonus.
The best games to fulfill the bonuses, by a long shot, are heads-up cash tables. However, this conflicts with the amount of buy-ins you'd need to set aside and the variance may make it less valuable.
The best strategy in terms of deposit bonuses, is to stick to one site and build your bankroll up there, then once you have enough of a bankroll to get the biggest pending bonus on a site, e.g., 100% up to $800, where you have earned $800, then move to other sites, and so on. Don't try to get involved in more pots.