How do you wager casino bonuses?

I seem to do better by veering away from games that accumulate Jackpots which is increased by taking a percentage from every bet played.  Three reel & five reel games seem to work best for me. If a game doesn't hit within 5 to 10 spins, there are probably looser games to pick from.

All in all, enjoy the bonus of familiarizing yourself with the casino and its options.

Prosperous and pleasurable playing to You!

No, there is not. I just pick a game that will pay you out the most to get the wagering out of the way 

Try to find a "low volatility" game.
Low volatility means the odds of the games are set so you probably won't win much as well as not lose much. 
These are the steps I take to try and maximize my winnings from bonuses.
Assume I got some free bonus money let's say $50.
1. I don't try to wager those 50 bucks so I could withdraw them... With time I found that immediately trying to withdraw small amounts doesn't work well compared with playing bonuses on high volatility games hit once in a while a bigger win and then try wagering that win let's say $150 instead of the $50
Search for a high-volatility game. Many casinos show that information in the game details. Some sites show you the volatility score of a game can be between very low to very high. Very low being that your chance to hit is higher but each hit pays out little compared with very high volatility where your chances to hit are bigger but each hit pays out more
2. After playing some bonuses you might gonna hit 1 time and reach a point where you double the bonus you got. This is not a bad point to start thinking about playing just to wager.
3. Search for a very low volatility game in the same way. The details should be in the game details (depending on the casinos). But you can also ask their support chat to tell you which games are low volatility. Get a list of at least 5 games with very low to low volatility.
4. From that list choose the game with the highest RTP (which stands for Return to Player). RTP means how much the player should statistically see in their hands after a full round of wagering a certain amount (so if the RTP is 95% and you wager $100 you should end up with $95. Again this is only the statistics of how the game is set it doesn't mean that when you play you will get 95% RTP on your play. Sometimes you will do better some times you will do worse. Search for games that are higher than 97.5%.
That info should also be available but usually, it is not exposed by the casinos. Check with their support team or even better if you can find it on independent websites.
5. Hopefully wager on and cash out :) 
I always recommend going for free bonuses as much as you can I prefer to play with the casino's money and not mine when possible :) 
To be clear there is no real way to win... Dont, expect to win anything... The odds are against us... 😅 but I found this way to increase the chances a bit. I hope this helps