There are many tutorials for sewing the burrito style pillowcases out there. My favorite is this one:
https://youtu.be/tOaEHBKKiAU
It makes a very pretty pillowcase and they are super easy to make. One thing I do differently, I sew down the accent strip. I found that it tends to curl up after washing/drying.
Here is a nice selection of pillowcase patterns too:
http://millionpillowcases.allpeopleq...rns/index.html