Babies eat, sleep, and need to be cleaned, but as they get older they will start to reach for things that are not toys. My favorite saying is "That is not a toy". Babies, especially toddlers need to learn the concept of the word No, they don't already fully understand yet. Their first thought is well why not? Saying this is not a toy, and then giving them something that is: for one redirects their attention and for two explains why they cannot play with that object. When a child goes to the stairs, I’d say something like DOWN in a firm voice. Then I would redirect her and tell her "Let’s play with your ball, can you find your ball?" Also let your child know that it’s boo boos to play on the stairs. Then play with the ball together. Using positive reinforcement and using statements like "you need to", or "that's not a toy" or “Where is your ball?” is works better then “No, don't do that" Instead tell them what you want them to do, by using positive reinforcement.
Babies are curious and want to explore what is around them. It's okay to have a basket full of soft baby things that they can pull out and go through. I found this worked better for my house then letting her play in a cabinet that was child proofed. Also having a gate up and keeping things that the child should not be playing with avoids a lot of temptation. When a baby gets curious they want to touch anything they can get their hands on. It’s up to the caregiver to make sure that things that aren't for them to play with, or are dangerous are out of reach.
When a caregiver gives a toddler/baby whatever they want because they are screaming for it, then that makes it okay for them to act like that. They'll think, "Well I'll just scream till I get what I want." This leads to unbelievably bad behavior later on. The caregiver is in charge, not the one year old, and they need to know just because they cry. It’s not going to make the caregiver give in, when there is more than one caregiver for your child this issue needs to be addressed to each person caring for the child. When grandma lets baby play with anything they scream for, then the parent doesn't at home, it will be ten times the challenge to stop the behavior. Consistency is the key point.