I decided they would be better as one!
Well, mostly what I did was add the card slots to the pencil case. The pencil case pattern, as written, has slots for pencils or pens, and I prefer to keep those things in the zippered pocket. But I like having card slots.
To make the card slots, I doubled the length what would have been the of the pencil slots, and then added a few more inches just to be safe. I wanted to be able to fold it back on itself, so I could use it as a lined pocket. To make the card slots, I just followed the directions on the trifold wallet.
I overestimated the length slightly.
Or maybe underestimated. I wouldn't have minded a few more card slots.
In any case, I just cut off the excess and added it to my scrap bin.
I also lined the zippered pocket and the open side pocket. Lining the open side pocket was simple, I just added another piece of fabric behind the pocket before adding the binding.
For the zippered pocket, I put the pocket together like I sew all zippers. Then I pressed the bottom edge of the both the main fabric and the lining in 1/4 inch.
Then I was just very careful to keep them lined up when I sewed them to the pencil case lining.
And it worked beautifully!
I love my new pencil case, and I'm thrilled with the little tweaks I made so it is perfect for me!
If you would like to purchase the pencil case pattern, you can do so here and you can purchase the trifold wallet pattern here (both of these are affiliate links and I will make a small commission at no extra cost to you if you click on them).