When Punkin was 18 months old, it was clear that he knew I was the most important person in his world, but never looked to me when asked, "Where's mom?" He didn't know labels for objects or people, which is a common problem for children with Fragile X, autism, and other developmental disabilities. Here's what I did.
I used my digital camera to snap a bunch of close-up pictures of some of his favorite toys, people, and most important objects: his toy truck, his sippy cup, his high chair, me, his grandma, his grandpa, etc. I printed them at a local store and slid them into a small photo book. Then I wrote the words on the sticky labels and stuck them on the bottom of the pages. You can also print off the sign language signs off the internet and stick them on the page or slide them in the page next to the picture. Then just "read" them book with your child. This may be easier said than done, I understand. (My son loved being read to at that age, but he doesn't like it very much now.) Be sure to point out the actual object with the picture if possible. For instance, if you are on the truck page, point to the picture and say, "truck," then pick up a toy truck and say, "truck." This helps make the connection. If you can get the sign in there, that's even better. It's one more visual aide to assist learning. Sign is never a bad idea as long as you pair it with speaking. My son learned that everything has a name this way. It worked for us.
After he picked up a few words from that, I was able to make a communication board using those same pictures. I took the sippy cup picture, the blanket picture, and several others and used velcro to stick them to an old piece of furniture. I showed him how he could hand me the picture, while saying the word, and then get the object. This took a little longer, but it helped with decreasing the frequency of crying fits. And even if he was already crying, I could say, "Can you show me?" and he could sometimes find the picture of what he wanted from the board.
Once you get this mastered, you can move to Boardmaker, which is the standard program that is used in special education classrooms. It's expensive, so if you can't afford it, ask your speech pathologist or occupational therapist if she has it and can print some pictures off for you. You can also use clipart. The idea is basically that you're moving from real pictures to representative ones.
There are options for voice output devices as well. They range from one button switches that you can record to say anything you want when pressed to thousand-dollar multi-button electronic devices. For example, with a simple one button device, you press the button and it says, for example, "juice, please" and then the child either learns to press the button every time to fulfill that need or hopefully learns to say the words herself because she hears them modeled. Here are pictures of what these devices look like and an article about how they can help.
If your child does have Fragile X, it's been shown that results are best when eye contact is not demanded and when the instructor sits next to the child. Most activities should be play-based to ease anxiety and to get the most out of the sessions. It's sometimes difficult to convince professionals, specifically speech pathologists, not to demand eye contact, because they think the child isn't listening. This is not the case with children who have Fragile X. Allowing them to look away increases their ability to concentrate and take in information because it isn't as visually stimulating.
I hope this information helps. I'm certainly not a professional myself, just a momma who's been through a lot with my kiddo. If you need articles or advice from experts, the National Fragile X Foundation offers their Foundation Quarterly online through their website. They have really good information in those. It's along the right-hand side of the front page. Also, you can email them and they will email you back. I have done this several times and they have been very pleasant and helpful.