There are a few ways you can thicken your hair.
One quick way is to get a haircut that includes layering. Layers can help give your hair more volume.
Another quick hack to thicken your hair is to use a volumizing shampoo and conditioner
If you want to permanently thicken your hair naturally, then it will be a time-taking process. Here’s what you can do:
Apply hot oil to your scalp thrice a week, as it stimulates blood flow in the scalp
Take a protein and omega-3 rich diet or personalized hair supplements
Apply a hair growth hair mask once a week.
Avoid heat styling tools and make some lifestyle changes for faster results.