Lay out a sheet of pasta. Place your filling on it at a comfortable distance (be sure your surface is well floured or the dough might stick!).
Place a second sheet on top of the first. Use your fingers to seal the stuffing well. Ensure you remove all air or they will be likely to break open when boiled.
Using your pasta cutter of choice (I'm using a stamp in this photo), break each ravioli from the sheet. Store them wrapped in wet paper towel until you're ready to cook (up to a few hours).
Place the raviolis into a pot of boiling water (heavily salted).
When done (doesn't take long at all - maybe a few minutes or five), carefully remove from the water. Your raviolis are ready for their sauce!
Notes
For the homemade pasta sheet, see my recipe for Italian Pasta Dough. I like to use a thickness around 7 for ravioli.
It's important that you seal the raviolis well and that you handle them gently throughout the process. They are fragile and will break open if you don't.