at a clip
1. In a particular interval or span of time. I don't feel like going out tonight because I've had to sit in lectures for five hours at a clip every day this week.
2. At a particular pace. In this usage, an adjective describing the pace is used between "a" and "clip." Since you're still a beginner, just see if you can get your horse to move at a steady clip.
at a good clip
Quickly; at a fast pace. That horse is moving at a good clip—I think he might win the race!
*at a good clip
and *at a fast cliprapidly. (*Typically: go ~; move ~; run ~; travel ~.) We were moving along at a good clip when a state trooper stopped us.