Well Gs start from Primary Flying Training during Mushshak. After getting solo, a cadet starts the maneouvers. From loop (4-4.5g), barrel roll (4 Gs) and so on in aileron roll, cuban8 and other maneouvers. Once on jets Gs become intense so one needs a G suits which decreases G effect by around 2 Gs.
By the time a guy reaches ACM stage he is very used to of Gs. Before we start the actual combat, we so some light maneouvers, which is called G warm up so to avoid the G-loc.
During combat Gs vary from -1 to +6...its quite a variation in a very short span of time....I remember during my days on F-6, that was one wild horse to handle during combat. With its swept back wing , it was so easy to go into a flick or spin during combat. But it was fun, specially during slow speed and gun ranges.
Aircomabat is no doubt the best mission one can fly during his / her tenure on fighters.
Cheers