One important part of feeding your baby is making sure they do not get sick. This means never giving them expired formula or breast milk, and making sure you recognize an allergic reaction when they try something new. Baby bottle cleaning is important, but you do not want to overdo it. This can also extend to making sure the parts of your breast pump that touch milk are kept clean as well. There is a balance between keeping them clean and your baby safe, and going too far with it.
The most common means of baby bottle cleaning is the easy to use bottle brush. These are not simple any longer, as there are many companies that make their own version. If you use simple bottles, a simple brush will do. However, if you have a more complicated bottle, like Dr. Browns, you have more cleaning to do and some brushes are going to work better than others. Thankfully, brushes for baby bottle cleaning are cheap, so if you don't like the one you got, you can always try out a few more to find the one that works best for you.
Some of these brushes wear out faster than others. There are very few, if any, brushes that are going to last the full year that you are going to use bottles with your baby. If you exclusively breastfeed and do not have to use bottles at all, this obviously is not a problem for you. You can, however, use these brushes to keep your breast milk containers and accessories clean. Some of the best ones have arm-like sponges on the top, but those do wear out. If you find one that you like, buy more than one so you have extras when the inevitable breaks occur.
There are means to sterilize your feeding accessories as well. These types of baby bottle cleaners look like small humidifiers or a mid sized makeup case. You put the bottles, nipples, and any other parts inside of them, close them, add water, and they steam sterilize everything. You don't want to do this after every feeding, as that is overkill. There is a such a thing as too sterile. You can do it often when you baby in newborn, but lighten up after a while. Every few days is good at first, and then once a week for all parts works just fine later on as long as you care cleaning them properly in between each feeding.
You can also find simpler means for baby bottle cleaning and sterilizing. There are bags made to hold just the right amount of hot water and instructions for what parts can go into the bag. The bag is then put in the microwave per instructions. They steam clean your items, as well as breast pump parts, for you in minutes. Some dishwashers can do the same as long as you use the right cycle and as long as you find a basket designed to hold nipples, rings, and pump parts securely so they do not fly around inside the dishwasher. They go on the top shelf of the dishwasher and safely clean everything as long as you follow instructions.