Instead,base your forecast on sensible proverbs that have stood the test of time.

what correction should be made to this sentence?

The only correction I see is there should be a space after the comma.

The sentence "Instead,base your forecast on sensible proverbs that have stood the test of time." should be corrected as follows:

"Instead, base your forecast on sensible proverbs that have stood the test of time."

Correction: Add a space between the comma and the word "base".