Does anyone have any tips on this? Or tips on how to appear more confident and positive in the meantime?

I'm trying to make a point of graciously accepting compliments, and not saying negative things about myself to other people.

My internal problems will take a lot of time to fix, but I want to at least outwardly be more confident. I know low self-esteem is unattractive and off-putting, and can give off very negative vibes (in both romantic relationships and everyday interactions). I want to be someone people are happy to be around, and not someone who needs other people to cheer them up.