When you choose your hashtags for your posts, you want to think about your demographic. If your content is funny or if it's more informational, you should find hashtags that align with people who will want to watch your content and begin following you. Here is how I generate TikTok keywords that are effective for SEO:
Choose long-tail keywords with under 100k volume to begin focusing your efforts on
Update previous posts with new keyword selection
Select high volume keywords that are your final targets
Use a combination of both long-tail and high volume keywords on your posts