You did not say what type of applique you are doing. Hand or machine, raw edged or turned? My fav is raw edged and decorative stitches and using fusible to hold it all in place. I go through my stash of thread and pick what ever I think will look best. Love the machine embroidery thread for this - it shines!
I know how to do hand applique - but like others on here - getting the arthritis in the old hands. But, remember, there's no stress on the applique like there is on seams in clothing. Your quilt, your call. We are all "artists" here so be creative.