Since surfaces were removed, a part of my workflow has been disrupted because I often need to know which face of a Part is which, and I used to highlight e.g. the Front face by selecting the FrontSurface property in the Properties window, which would show a small yellow border around the face.
Today I finally got too annoyed by this and made a plugin that fixes this for me. You can install it by following the link or you can download and install it as a LocalPlugin: FrontHighlightPlugin.rbxm (2.2 KB) (download, drag/drop into open place in Studio, right click, Save as Local Plugin).
If exactly one BasePart is selected, it highlights the front face of it like so:
Otherwise it just gets out of your way. You can toggle it on or off with the Toolbar button or by binding a keyboard shortcut:
I decided not to add functionality to highlight other faces, because they can be deduced by selecting the Move tool (Ctrl + 2) and entering Local transform mode (Ctrl+L), which is indicated by the little L.
If you want to change the color or highlighted face, locate the SurfaceSelection object in game.CoreGui and modify it. This change will be remembered on a place-by-place basis.
Let me know if this is at all helpful to you! 
And if you’ve got suggestions for improvements or features to add I’d love to hear them!
EDIT: I’ve become aware of a different plugin that does this and much more, but I’m leaving this up in case it’s useful to someone 
