Summarize this article:

Let the baby play with toys with a variety of textures. You can also encourage play with a variety of baby-safe objects around the house. Your baby is absorbing information through touch as they play with these items.  With this in mind, try to get your baby a little time outdoors every day. Exposing your baby to different sights, sounds, and experiences keeps their brains engaged. Do tummy time a few minutes a day to develop strong neck and back muscles and keep your baby interested in their surroundings. Babies need to practice their gross (large movement) and fine (small movement) motor skills. Things like blocks and stacking toys help babies work on grasping early on. As your baby gets a little older, balls and straddling toys will help get them moving. As your baby starts moving and crawling, give them a safe place to explore. Exploring helps them learn about their environment, and it creates the building blocks for spatial intelligence, helpful in things like navigation, mathematics, and sports. Make sure you remove anything the baby could put in their mouth (and choke on) and cover all electrical outlets. Also, remove any kind of chemicals (including household cleaners and even cosmetics) your baby could get into. You can use baby gates to keep them out of areas where they could get into trouble. Babies love playing around in messy textures, and letting them have some free rein gives them a chance to explore the physics of these objects. Finger paints, mud, sand, and water all make great textures for babies to play in, though of course, you should supervise them closely (or join in the fun yourself!). Bath time is a great time to learn about things like how cups are filled up and how gravity works. That is, you don't have to actively teach these things to your child; just give them toys to play with in the bathtub. With a set of cups, most kids will start pouring water back and forth, for instance, which helps your baby learn about things like volume and gravity. Use your grocery store time to engage your baby. As you pick up different fruits, for instance, say their names and let your baby touch them before you place them in your basket. You can also do things like count items as you place them in your cart or say what you're going to do with each thing. Repetition, such as talking about the same fruits every time you go to the grocery store, helps your baby build neurons and create lasting memories.

Summary:
Offer a variety of textures. Provide toys that help with motor skills. Baby-proof your home. Let them get a little messy. Take toys to the bathtub. Keep them entertained at the grocery store.