For spades and hoes, work slowly and evenly along the edge without affecting the strength by making it too thin.
If frequently dulled after use, they might not be up to the task. Secateurs will work best on items no thicker than a felt tip and loopers cut chunkier growth, up to the width of a £2 coin.
Whereas a pruning saw will cut through thicker objects the size of a jam jar lid. Of course, spare a thought for your hand protection when cutting, pruning, or working with thorns.