Is your hope to keep it exposed? We’ve done a few affordable ceiling ideas you could consider: https://www.frugalfamilytimes.com/search/label/Ceiling?max-results=9&m=1
Lightly sand and use a penatrating stain so the wood grain comes through
Is it structural? Do you want to hide it or enhance it?
I want to enhance it. We had to place sister joists and now I wang to cover or stain the beams and use some lighter color in between. Looking to create height as well as fit in with rest of post and beam house.