Componets of any trade

There are three things that make up all options trades
1. Price (delta)
2. Time (theta)
3. Volatility (vega)

Most of the time price is hard to control so you must rely on time and volatility.
Time is just selling premium. To generate a monthly income you need to sell premium and let time decay work in your favor.
Volatility is select strategies that will capitalize the change in volatility. Calendars are great for options that will increase in IV such as earnings and when IV is near the low of historical IV. When IV is higher than normal than using credit spreads will benefit the most.