There is no great formula to increase client responses. Even if you are a top-rated freelancer, with a high JSS and well-written proposals, there is a lot of competition on Upwork, and getting new invitations can be a challenge.
You may wish to review Growing Your Upwork Sales by William T C; it may provide a few ideas you can try. Plus, there are hundreds of other posts with tips to help improve your profile and proposals, which may ultimately help increase responses and invitations.
