Here are some thoughts yet not sure what flexibility you have in your images since you cannot share. I am assuming that you want to make the text less blurry and more readable.
- Sometimes size reduction from an actual text Layer instead of from a rasterized Layer has better results.
- A different text font can make a difference
- Bold version of font may look better
- If you seeing pixelated edges on the text actually adding a bit more blur and help readability
- Having higher contrast between the text and background makes a difference so choice of text color and tone can make a difference.
- Another option is to stroke the text in Layer Styles as a way to increase the contrast
- Staying away from lossy compression formats is helpful until the very last step (that may not be an option for you if you are starting with a JPEG)
- If you do have control over the JPEG, choosing the highest quality compression setting helps
I know these are general suggestions yet without a target to aim at, its hard to provide more specific recommendations
Hope this is of some help
John Wheeler