When your baby has caught on that there is a sign for everything, she will look to you to show her the sign for whatever interests her in her environment. When our son was in the explosion phase of signing, I tried to be prepared for whatever new signs he might want to learn, especially if we were going out on an excursion. Now that he’s a little older and knows almost 200 signs, he’s patient enough to wait for me to look it up when we get home.
In order to keep the object or action at the front of his mind, we talk about it while looking at it, then for awhile after, and again when I teach him the sign. This becomes so much easier if I have my camera with me and can take a picture! That way, when we get home, I can remind him of the new animal he saw on our trip to the pet store, for example, by showing him the picture and teaching him the sign. We can then revisit the picture again and again as often as he likes and solidify the sign in his memory (as well as the word now that he is talking).
So many people (babies included) are visual learners, so take your camera with you all the time and take pictures of the things you will sign about with your baby. She will love to look through them and show you that she remembers the signs for all of them!