I’m kind of new to the Guilty Gear series. I started with Sol, because he seemed like a simple character. Here’s what I got out of it so far:
Strats:
-I don’t find Sol’s Overdrives to be very useful. Dragon Install is garbage, seeing as the opponent can play it safe until you run out of DI, and when you DO run out of DI, you get raped for free. Tyrant Rave isn’t half bad, but it’s a waste of meter. I find that Sol puts RCs and FRCs into very good use, and the majority of his Tension meter should be used on that.
-My main strategy with Sol is based around pressure, and a huge part of that is Gun Flame. I find it to be a good way to safely end blocked combos, and if you FRC it, it covers you for another rush. After Gun Flame into FRC, run in with a low kick, if it hits, finish the combo. If it’s blocked, you have tons of options: pressure some more into another Gun Flame (FRC), go for a Dust, go for a command throw.
-I find Sol’s Loop Combo to be really important to his game. The fact you have it threatens the opponent every time he gets close to a corner. Even if you don’t end up hitting the opponent with it, it works to your advantage. Obviously, the more setups you have for it, the better (I’m still working on that).
Combos:
There are probably stronger combos, but I either don’t know them or can’t do them yet. 
Anywhere:
-dash, c.K, s.S, c.D, Bandit Revolver
**Standard B&B (Does anyone have anything else??)
-dash, f+s.P, s.S, c.H, Jump, j.S, D.Jump, j.S, j.D, Volcanic Viper, Knockdown
**Not as practical as the last combo, but it does good damage
-command throw, dash, c.H, S.Jump, j.S, j.D, Volcanic Viper, Knockdown
**This is the best combo I can do after a command throw. I’m having trouble doing a double-jump combo after a command throw at midscreen. Any suggestions??
-s.D, Jump (Hold Up) j.D, j.D, j.S, j.K, j.S, j.K, j.S, D.Jump, j.S, j.D, Volcanic Viper, Knockdown
**I have a hard time with the double-jump part, but I’ve done it before so I know it’s possible. It shouldn’t be too hard though. Otherwise, just do the Volcanic Viper instead of the D.Jump.
Opponent in Corner (Dust Loops):
(Replace “Dust Loop” with: Jump, j.D, D.Jump, j.S, j.D, Land, S.Jump, j.D, j.D, Land, Jump, j.D, D.Jump, j.S, j.D, Volcanic Viper, Knockdown)
-dash, f+s.P, c.S, c.H, Dust Loop
-jump-in, j.D, dash, s.S, c.H, Dust Loop
-command throw, dash (under), c.H, Dust Loop
-Gun Flame, FRC, s.K, c.H, Dust Loop