The most common elixir/gold raid strategy up until around TH7/TH8 is BARCH. This strategy basically targets undefended (or lightly defended) collectors near the outside of mostly abandoned bases. The article I linked has examples of what to look for, what to train, and how to maximize your raiding efficiency.
You basically don't want to be punching into the center of bases, just attacking the "easy money" around the outside. It involves a lot of skipping, either because the base doesn't have enough resources or they're not in undefended collectors.
Spell wise, you can take lightning to kill mortars that would normally trash your barbs/archers. Earthquake can be good too, but it relies on DE which might be at a premium for you.
If you've got DE to burn (chances are you don't, but still...) try adding minions to the mix, this strategy is referred to as "BAM." Sometimes, people mix in wall breakers to punch a little further in, it's worth experimenting with to see what works for you at least.
The December 2015 patch changed the meta significantly, so now it's actually useful to hit town halls and/or earn stars when attacking. Make sure you've got a clan castle (and join a clan if you're not in one already!) to hold the star loot.
As I got into the higher stages of TH8, I started switching out the barbarians for PEKKAs. ("PARCH?") Even though it seems like PEKKAs should be a waste, if you can hit higher level bases and take more of the collectors, it ends up profiting anyhow. If you train 1 PEKKA per barrack, you can use overtraining to always have a set ready and/or get 2 nearly back-to-back attacks.
For that strategy, I suggest taking heal spells to make the PEKKAs last a bit longer.