The three S
Spin
Spark
Spray
Hopefully in that order or there may be big problems.
To start one, you need to pressurize the burner. before you energize an ignitor (spark type plug) and introduce the fuel so it gets atomized into a mist fine enough to burn *in the burner*
In order to pressurize the burner you need to spin up the compressor rotor that feeds the burner. This requires either an air driven motor of some kind or lots of ram air speed coming in the front (air start)
So far you've got lots of good answers hollar if you want more.