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.

Setting an Object pivot point
We have an Object that in our game engine needs to pivot around a particular point. We can do this in Blender by using the 3D cursor.
First create an empty axes Object, and place it where you want the object to pivot around. Click on the axes, hit Shift + S

The 3D cursor will snap to your empty axes.
Next select your Object, in my case it's the front axle of this bike. Click on Object->Set Origin-> Origin to 3D Cursor.

The Object will now rotate from that pivot point. When you export to Unity and rotate the mesh, it will rotate from that point.

