Ok my grandmother was the best gardener I ever knew.She said to leave things alone if you wanted flowers and fruit.Then when they had finished that stage was the time to hard prune them back,usually in the Autumn.
So it's up to you and depends entirely what you are growing.
If you want apples and rose hips you need to let them go through the cycle and then prune.If you want more Rose flowers you need to dead head them to encourage a later budding..
To be honest a damned good gardening book would be a help.Those very cheap books by
Dr D G Hessayon are really good.They are easy to understand and a very inexpensive.