Medela breast pumps are easily one of the best gifts for a new mom. I also would suggest some good literature on the first few days after birth, and maybe a reference call list. Another great gift would be gift certificates to a food market, or maybe a lunch out.
Baby jewelry is a great gift for a baby shower! Go to http://www.cornerstorkbabygifts.com/baby-jewelry.aspx to find a great gift for any baby shower.
Some unique do it yourself baby shower ideas include hanging baby clothes near where the shower is being held. You can create candy favors. For more ideas: http://www.ehow.com/info_8172828_do-baby-shower-decoration-ideas.html
One can find neutral baby shower ideas from many places. Some of the best sites where one can easily find shower cake ideas are baby shower, shower for life and many more.
If you gave a baby shower gift earlier than the due date of the baby shower then you do not need to give a gift, but if you just gave the gift not knowing about the baby shower you could give the mother to be a small gift for the baby.
Any type of baby shower favors are good for a twin baby shower as well. Chocolates, little photo frames etc. You can find some ideas here: http://www.prettybabygifts.com/baby-shower-favors.html
Baby shower decoration ideas can be found in plenty online. Another way to gather ideas is to talk to some friends or family whom have already had children and a baby shower for input and advice.
Yes, Macy's does sell baby shower gift tags. You can find them on their site where you can order them, or you can go in their store and grab some gift tags.
Some unique ideas for a baby shower can be clothes, or home-made cards. For cool ideas, maybe something home-made would be really nice for the baby. Something for the room when the baby grows up.
At this website, you can find lots of baby shower ideas, and how to throw them. If you need some products to go along with the baby shower, they are sold online at that website as well. http://pregnant.thebump.com/pregnancy/baby-showers.aspx
Some times it is difficult to decide what gift's to give for a baby shower. Advice can be sought from a web search and sites such as http://www.babyshower101.com and www.babycenter.com should start you off in the right direction to find the perfect gift.
Some ideas for homemade baby shower favor boxes can be done with ribbons and nice packagings for the favor boxes. The baby would absolutely adore it and it will be great.
There are many online sites where you can get ideas for baby shower cakes. Some of the best sites are baby cakes, wilton, parenting, parent connect and many more.