Tips for cooking pasta twice
In college, I would oil the pasta lightly after cooking (so it didn't turn into a giant lump), then would steam it 'til it was warm, and add it to hot sauce.  I was typically working with linguini or other strand pasta.  I'd start it in the steamer for a bit, then turn the mass over.  As it softened up, I'd lift it with a fork or tongs to re-distribute it, and try to break up any lumps.

These days, I'm more likely to use a microwave than steaming.

You can also portion it out into oven-safe containers w/ some sauce, maybe a cheese or breadcrumb topping, and reheat it in the oven.  This works well for any size/shape of pasta (although I admit I've never tried angel hair or similar size, as I hate cooking them).  Reheat covered at 300 to 350F, then once the middle is warm, uncover and brown under the broiler