ctrl + shift + o: opens the “Download object” dialogue, allowing you to download by ID

A whilst in node drawing mode: toggles accurate drawing mode, allowing you to align to common angles and with previous points. You can also hold ctrl and hover over another way to draw parallel with it

ctrl + alt + v: paste copied object into the source position (i.e. where it was when you copied it). Useful when working with multiple layers

5: zoom to downloaded area

4: zoom to conflict

ctrl + h: display history

holding ctrl while drawing a way starts a new way from a point

shift + j: join overlapping areas

alt + shift + f: opens the filter dialogue allowing you to hide certain objects