I don't have a depth finder either. Usually I pond hop because I have a young family that demands most of my time. And you'd crap yourself if you seen the private waters I have access to. Such a treat. Anyway.
I do have a small Jon boat and kayak. Without any electronics (I hope to fix that this year , but I have to keep the lights on) at least a depth finder would be nice. The thing is , I almost always manage to find fish... When I do get out on lakes they are usually less than 500 acres. The biggest being 3000. The best advice I can give is to find the baitfish. No matter what the forage is , if the little ones are around.. so are the bass. Shallow areas next to deep ones almost always hold fish.. my favorite are coves ! They are almost always stuffed with fish... Weedlines, timber, docks, and rip rap all help me locate bass without electronics.
Find the forage next to cover and the bass are there.