When we did our first DE cycle. I thought twins would be overwhelming, so we only transferred one. Unfortunately, that cycle turned out to be a chemical pregnancy. The second time, we transferred two frozen ones - and one took, with a really good beta. My RE says that even if you transfer two, there's only about a 20% chance of twins, so I would tell you to go with what makes you the most comfortable.
Regardless, I wish you the very best of luck this time!!!