If you have a lot of clipping to do, you may want to try powered equipment. Look for something compact in size so it can be positioned precisely. A fast cutting speed is needed to provide the quality of finish required for topiary foliage.
Two new machines you could investigate are the UH200DW and HM164DW cordless grass and topiary trimmers from Makita. Both units are powered by 10.8V lithium-ion batteries housed in the handle. Fully-charged batteries should give around 30 minutes of continuous running at up to 1,250 strokes per minute.
Weighing just over 1kg, the UH200DW is a fixed side-facing trimmer with a 20cm-long side trimming blade and chip receiver. The UM164DW also weighs around 1kg but is forward-facing. It has a 17cm shearing width with height adjustment between 10mm, 15mm and 25mm. Blade replacement on both items is tool-less.
Sally Drury has reported for HW and its forerunner GC&HTJ for 28 years and has spent more than five years testing machinery for HW and What Kit? The advice in this helpline is independent.