Not sure the size of the airfield you fly out of but I am doing my PPL at a very busy field and I have certainly been taught to do an initial "Tower G-ABCD" call.
The most usual response is to standby and then when the tower has a moment they ask for the message.
Seems to work pretty well and gives the ATC guys a bit more control.
The RT book I have recommends that the initial call is a radio check which achieves the same thing I guess. Nice short call that then gives the ATC the chance to ask you to standby or pass message if they are ready.
The request taxi call can be a little lengthy...
Tessract