First off, welcome to this tutorial about cutting thing to an angle!
Let me go into this with more detail.
You can watch a very half-assed video I made where I made a lot of mistakes and show you that I have a rather bad habit of selecting things I'm cutting over and over before cutting it again. I got into this because you have to select the bit you're cutting to deselect the bit you just cut (so you don't pointlessly cut a bit you don't need to) when making concave curves. It may help you though. It also shows how I made the fans in my Fan Prefab Pack.
Link is here (save target/link as(may take a while)).
May be easier if you use the "Paste Special command" rather than manually doing this process multiple times. For the values in the "Paste Special", there is a special trigonometric algorithm for determining what values to set for the rotation and x, y shift. I remember it was up on one of the big surf mapping forums; I'll see if I can find it...
I must say this is brilliant! You can also use this technique to make roads! because the texture rotates along with the brush if you make your rotation small enough you can make a perfect turn!! its really amazing!
Mapper
P3: Peasant
Points: 7,585
E2: Guide
EF: 26
C2: Ripe Member
A4: Graduate
Account Age: 4 years
Fibbs
You can watch the video and refer back to this tut :D
I didn't really want to post the vid because it was badly done and done in a rush while half-asleep. :P
I thought it might be useful for someone to see it being done though, even with the mistakes.