I use those Nunn tablets once in a while. Lemon-lime with caffeine, but only 1/2 tablet in a large water bottle. Really salty, makes you drink more. Keep an extra bottle of clear water available.
Sometimes I will take iced tea with me.
Don't like the gels.
Snack on salted almonds or pistachios, walnuts, pretzels, etc. Whatever you got, bring just a little of everything. Be creative, it's not complex.