One of the hardest things about photo editing is you so often have to make your image look worse before it looks better, one example is the curves the final result of the curves depends on how you move all three of them BUT you can only move one curve at a time so you are making your image look worst before you can make it look better, and this is the same with just about all tools in Lightroom because they are all interlinked.

So if you mess up one tool it messes up everything. You apply presets and it doesn’t look very good, but there is a good chance you are only one or two adjustments way from it looking great. It only takes one tool to not be quite right which ruins everything. So the only way around this is to understand in-depth what each tool is doing.