Pruning is the subject of many, many books & beyond the scope of anything we could share here, unless the questions were specific. If you wish to learn how to prune, gain a thorough understanding of apical dominance and how what you remove from a plant influences the growth of what you allow to remain. Without an understanding of apical dominance, proper pruning procedures will likely remain a mystery. With an understanding, you'll be able to prune with confidence & the knowledge that your efforts will yield the desired result.

As far as what to prune, we all have our preferences & ideas of how we wish plants to look. I have some plants that are pruned to topiary shapes, some that are only pruned to enhance their natural shapes, and some that I like au natural. Beauty is in the eye of the beholder when it comes to pruning, but I find a sound knowledge of pruning is helpful even when it comes to keeping floral displays of things like petunias, calibrachoa, torenia, impatiens, coleus, and many others looking attractive. Where, when, and how to pinch garden and container plants also comes as a byproduct of learning to prune properly.

Good luck.

Al

I bought a beautiful Calibrachoa hanging basket a couple months ago and it was quite full of blooms and now the flowers are sporadic, I am pretty new to the horticulture world and are eager to learn......should I cut back(give hair cut) my Calibrachoa so that it can thrive?. How can I get it to come back?