In order to take full advantage of the magnification of a spotting scope, you should use it with a tripod to stabilize your view.
The tripod you use will mostly depend on the size, weight and focal length of the scope you have.
Tabletop tripods extend 6-12 in, carry up to several pounds, and should only be used for the smallest spotters (such as Mini-MAKs and LandScouts). Besides the low weight capacity, these tripods often can’t stably tilt back to look very high and have to be used on a flat surface, limiting their usefulness. Their advantage is extreme portability.
A lightweight photo tripod can carry weights up to 10 lbs, can stand up to 65 in high, and usually has a ball or pan-type head allowing stable pointing in all directions. These are an excellent choice for the vast majority of spotting scopes, and are recommended for apertures up to 80 mm. They are still light enough and can be collapsed to a reasonable size for convenient carrying.
A medium or heavyweight photo or video tripod can carry weights up to and beyond 25 lbs. Use these platforms for the heaviest, longest focal-length spotters, like the Regal M2 100ED, C90 and C130 MAKs, and the C5.
For astronomy or the most stable terrestrial viewing and photography, consider using a telescope mount that can be adapted to hold the 1/4x20 screw needed to attach a spotting scope.