Guile is usually a character we should play in defense.
One strategy you can adopt is to mater distance and send SONIC BOOM.
If the opponent approaches, you get down preparing the FLASH KICK
If he jumps, you apply the FLASH KICK
If he walks towards you, you apply a medium low kick. That is, a rasteira.
This strategy, although simple. It is very powerful.
I am an advanced player, but even today, much of my design technique is based on this strategy