Go arounds can happen for any number of reasons that as a controller you cannot prevent, however, if this is happening regularly then maybe you should examine your procedures.
Most pilots trust the controller will issue a sensible clearance that will give them plenty of time to lose their height/speed. Usually they will comply with the instruction first, then try and make the approach work.
Maybe you have got into the habit of expecting too much from them and should wait a bit before clearing them direct? Maybe there are other factors involved which the pilot would be happy to explain to you. Just ask.