Terry cloth bathtowels or bathrobes, chenille, and flannel are also textures. You'll notice she's 'ready' when she gets a handful of new texture and sees to grab and re-grab it (repetition will be important). Her brain will probably just do this to cause observable behavior like that for you. You won't have to sit her down and have organized experiences. Other tactile things are having the breeze on their face when outside, or soft silky textures on the face.

Using lotions or sands may not be a good idea. Those things are not meant to be taken internally and if your baby is like most they'll tend to want to feel things by mouth.

Finger foods and 'self-feeding' or at least um tactile exploration of foods is a way to get a lot of stimulation opportunity with things they can eat. She probably won't be able to feed herself well, but she might enjoy playing in some pasta or cereal and some purreed fruits and veggies.

have fun, and try to follow her lead

I started when my DS was 3 months old, because I had read that that is when their sense of touch develops. He didn't really seem to notice. He is now 7 months old and he is very interested in different textures. He likes it when I wear velour pants. He is always reaching to feel them. We also have a touch and feel book that he likes. Other than that, we just give him lots of things from around the house that have different textures.