Stick to the basics: small appliances, linens and kitchen items (pots, utensils and other gadgets). However, I think the best way to go is Gift cards!!!
First of all, you really need to look over the couple's registry list at the stores they provide and then go from there to determine what is within your budget range. If you cannot afford anything from the list then try thinking of something unique that you would have liked to receive for your wedding that is practical and inexpensive.
My favorite wedding shower gift was a step stool. It was the most useful thing I received. It was wrapped in big bath towels and hand towels and wash cloths that were safety pinned together. I'm short and our first house had tall cupboards. I had to stand on the stepstool to get to the bottom shelf on the cupboard.
Personal shower get her a bit more racy like sexy lingerie, or a cozy bathrobe and slippers to make her feel comfortable. get a bit more creative and A day at the spa to relax? With all the running around she's about to start doing. Get her a gift certificate to a fine salon to get her hair and makeup done.