My most successful method by far(at this time of year) is fishing 'on the drop' with tares and hemp (and single reds) so by definition to have the bait dropping through the water you need to be casting (almost) constantly. It is a very busy and tiring way of fishing over several hours so I tend to leave the bait be for (say) 10 minutes after a non specific number of casts, but as John Step says above, if the roach are feeding and really going for it the float is rarely still.
I also tend to start with hemp (again with same method, as it has the effect of 'searching' the swim) and I can easily work out where the fish are taking the bait - i. e. at the top of the drop or further down in the water. I then introduce tares ........
Mikench: Taking lots of different baits is fine, but I suggest a specific hemp/tare session(s) might yield better results. Tare fishing can be a method that takes some time to develop (I have persevered for an hour or more before starting to take fish!) and on occasion they just don't want them, for some reason.
You are, by your own words, an impatient soul and I think just taking the hemp/tares would (perhaps) stop you from changing to another bait just because the tares might not be working! They do take time but without doubt produce better quality roach at the end of the day - on my waters at least!
Personally, I think total success with tares, in most cases, comes down to quality of bait and preparation and I spend much time in that pursuit.
ps Don't forget the water pistol (loaded with the perfectly strained hemp cooking juice to send a milky liquid down through the water. Much the same as liquy bread works..........................A mucky process but it works well at times!