You'll get a message at the start of the next round. I haven't hired a coach for a while so I don't remember the exact language, but something like "I like that offer very much" is the best. He might ask you to "tweak" it, in which case change it maybe 10%. He might say it is "interesting," in which case change it maybe 2%. These are just guidelines that worked well enough for me to get all the coaches I wanted (probably more than I need).