Utilize the usage of tags

[CyberMango]

Choose a form of tag files - catgs/cscope/gnu tags/global tags/universal ctags and integrate it into your vim setup.

Tags are useful for nearly all languages, and can be used for languages i dont have an lsp for, or for cross-language projects. They are also useful for symbol-based navigation, jumping to symbols from comments and docs, and in general are a complementary feature for an lsp.