I think the hardest part is picking a resort. It came fairly easily for us, but that is just a fluke. Have you ever been to the Riviera Maya? If not, talk to people who have. (For example, I would recommend Grand Sirenis!) The very first thing is to look at yourselves. What is important to you? What do you and your FI like to do on vacation? Are you lay around the pool people, or do you like to go-go-go all the time? Super active, sightseeing, swimming the whole time...? Is the view most important, or the food? Also, decide if you want adults only, or family friendly. And decide if you want to go all inclusive or not. Then, look at the makeup of the group that will probably be traveling with you. If it is a family-friendly resort, how kid-focused do you want it to be? Some places have great kids programs, so mom and dad can relax while the little ones go play. Or maybe elegance is very important, with fine dining and luxurious amenities. Maybe you have history buffs who want to see the mayan ruins (amazing!) or would like to try their hand at snorkeling (also great!). Or maybe it is a big party crowd, who love to drink! Look at your friends, your family, and yourselves. Then, start researching! If you are not leaning towards certain places or chains, research lots! Some places have incredible snorkeling, but have long trips to ruins, for example. Some places are close to Hidden Worlds, or Xel-Ha, or Xcaret, for the nature lovers, but farther away from the party scene in Cancun. Do you think you would like a big resort or a small one? There are lots of things to consider, yes, but I would explore a few options online, then look at reviews. I really try to avoid tripadvisor, but if you take it all with a grain of salt, there can be some good information. Narrow it down to an area of the Riviera Maya, then to a few resorts, then research all of those to make up your minds. Or, you might be like us, and fall in love with a resort right off the bat (we are going to the Dominican). Biggest factor, though, is what YOU want. Once you figure that out, picking out the resort becomes much easier.