Find out what keywords your competitor uses and how often and compare it with your own page. Ideally, choose a competitor ranking above you, and find out which keywords to use more, and which might be overused.
LSI (Latent Semantic Indexing) keywords are words and phrases that are all about a particular topic. They help search engines understand the exact context of the content on a webpage. For example, if you have a webpage about "vegan recipes" some LSI keywords might include "plant-based recipes" or "dairy-free food".
These phrases help search engines understand that the page is specifically about vegan recipes and not just recipes in general. Using LSI keywords can help improve the SEO of a webpage by making it clear to search engines what the content is exactly about and how relevant it is to search queries.