Gamma only increases drastically in the last week or so of trading, getting higher as DTE get closer.
As long as you get out of the position at least a week out from DTE you are rarely exposed to any danger from Gamma. (this is my understanding).
Theta is the hardest one for me to get ahead of. That is how much a short option will grow as time passes. In other words, assuming you set up a premium collection strategy and your break-even boundaries never get breached, then the theta should be paying you every day. HOWEVER, there are other things that seem to affect the theta (Delta, and gamma).
Theta is a greek only worth worrying about if your underlying does not move at all, and if it was that easy we could all just sell straddles every day. But underlyings do move, and the math to figure out how much that affects your theta is pretty hard. Implied volatility also affects theta a lot. You can own a stock on earnings day that doesn't trade up or down after earnings are announced, but you still lose a ton from the drop in IV rank for the options.
Bottom line - options are very complicated, and the people who seem to do best trade small, take profits when they can, and are very careful about what underlyings they select. NOT losing money on trades is just as important as having winning trades.