Size a face of an angled shape along its' edges
Say you have this shape, and you want to move and scale the selected face up and down, but Blender is only allowing you to move along its x, y, and z axis and Grabbing with G is too imprecise.
Instead, you can Press G twice, and move that edge, it should travel on rails along it's perpendicular edges
Perfect, we can now move this to shorten the face.
Selective proportional editing
In this example we want to create a nice chunky curve, but only effect the top faces. When we proportional edit in this way, the entire axle in this cases will move when we edit the one face we want to 'peak' outwards. We don't want this, we just want the top (selected in the screenshot) to move with the edit.
What we can do is click Shift + H. This hides all unselected geometry on the selected object. Now when we edit, only the shown faces will be edited.
Now the axle is super chunky! To show the hidden faces, use Alt + H.
Mirroring UVs perfectly when applying a Mirror modifier
So we have our object created, and we've used a Mirror modifier. We've also UV unwrapped our mesh to our liking, but we want to apply the mirror modifier so we can add a texture on both sides. This is important if the texture has writing or letters that cannot mirror very well - like the sponsor logos I will add to my livery texture.
First off, apply your Mirror modifier.
You should notice the mirrored section of your mesh is now populated with editable geometry. With X-Ray turned on, select the faces on the newly mirrored portion of your mesh. You should notice the UV gets selected too, but seems to be on top of the other side.
We need to separate the UVs from this side. Move over to the UV Editor and hit Y to break any links between vertices of the two sides. Then hit G to move the selected UV side to where you want it.
So this is great...but it isn't mirrored.
Click on UV->Mirror->X-Axis. Boom. Mirrored UV.
