I have tried a number of different things with my teams over the years. One is of course just a screen share and use a drawing app or UML etc (Visio was common). But what I like right now is to use a document share app, specifically Quip for us, which allows everyone to open the document in real time and it supports drawing, shapes and text entry etc. Plus when you are done it is a saved document that everyone has access to so you have the documentation done now too, and if any changes are needed you have change tracking built in. It is far from perfect, but for most smaller teams it works well and doesn't require extra licenses or anything.
I will say none of these solutions are perfect, but I am also the person that still likes to write my notes and draw on whiteboards to let me think through problems. And doing that with any digital software just never feels as natural (or fast) to me. I may just be getting old, but even when I am just doing architecture drawings myself I write it down first (whiteboard/paper etc), then document it digitally once I have settled on something more well thought out.