The basic format of the follow-up was "Hey, you mentioned you'd follow-up in X days so I wanted to check if you are still interested in investing?". Then I would, if applicable, also add a line like e.g. "since we last spoke, we raised another $X from investor Y" or "we almost closed the part of the round dedicated to the angels and have only $X available".
I would send over a SAFE only if the investor agreed to invest and had completed the handshake protocol (https://www.ycombinator.com/handshake/).
I never did fundraising pre-Zoom/covid so can't compare, but the advantage here was the sheer volume of meetings we could do in a single day. I guess that in-person it would be easier to build rapport, but Zoom was definitely an advantage when playing the numbers game.
I assume that is because they understand there a lot of different reasons behind no's (bad timing, wrong stage, not excited about the area, ...) so it doesn't automatically mean something is fundamentally wrong with the company.
On the other hand, getting yes is definitely a big signal for others and makes them move much faster.
To me it all felt like a really fast game with a huge pile of deals on the table where everybody is just digging through and looking for something they like - no is here just a default answer and everybody has their own "filters" and premises they are going after.
This is why it really helped us when we focused really narrowly on finding investors who are a good fit for us, that was probably the biggest factor of all.