When angle accuracy matters (whether it's 90*, 22.5* or 75*), tradespeople building countertops, kitchen cabinets, etc. use this not-so-secret weapon as a last resort!
https://tinyurl.com/4pp8274u
That looks like it might be useful, I have never seen that stuff before ![Big Grin [big grin]](https://www.festoolownersgroup.com/Smileys/default/biggrin.gif)
Just be aware that the stuff called "painter's putty" is oil based and it takes forever to dry/harden. It is meant to hold glass to the sash, it makes a lousy filler. There are better options for that.
Durham's rockhard water putty comes to mind or ordinary autobody filler both work well.
As far as the original project of this topic, the famous "it depends" comes to mind.
In some situations and for most of the past years, it is just quicker/easier to template it. I have seen guys do it with cardboard strips, but 1/4" plywood or MDF strips are far more accurate.
In more recent years we would do that with a Laser Templator. This can then be uploaded to the CNC to cut out parts for Solid Surface tops, or particle board for laminate tops. On a job of solid wood like that it would likely just be cut out of 1/4" MDF for an odd shape or just transferred to a measured drawing for simple rectangular parts.