You can get perfectly accurate angles - any angle - with a bog standard mitre fence.
The tool you require is called a Sine Bar. It's a shaped piece of wood with two circular anvils in it a known distance apart. I'd post a pic but mine was part of the Haul, along with my (fairly decent) mitre fence. I didn't use it often but I do miss it for some jobs.
Let's say the anvils are 10" apart. It's a handy size. The sine of 45 deg is 0.707. Multiply this by the size of the sine bar, in this case 10 (which is one reason why 10" is a handy size). Cut a piece of hardwood 7.07" long and use it against a roofing square to set the angle. You don't use the scale on the miter fence at all.
There is a much better explanation of the method on one of my DVDs, I forget which, but it will be 9 or 10. And I wouldn't be surprised if there is a TY video about them as well.
I know it sounds complicated but it isn't, and once you have made the block, label it and keep it safe for next time. A 5" block will give you exactly 30 degrees (because sin30 is 0.5).
One of the advantages is the repeatability and the ability to set it left or right-handed with equal ease and accuracy.
If anyone has a standard fence they no longer use, preferably one that fits a standard 3/4" slot, let me know, will you?