Paper Towel and Ziploc Bag Method
Clean and peel your Avocado Seed.
Wrap your Avocado seed in the damp paper towel.
Place them in a ziplock bag.
Store away where you know it will get humidity. I had it on my window sill at first but then moved it to the cabinet under my kitchen sink when I didn’t notice much activity. (Either way would work)
Wait a couple of weeks and keep checking in on your seeds. You can change the damp paper towels if you want to as well. I don't always do this, but it only helps, just not that necessary.
Once you notice some roots growing, you are on your way to growing your avo plant. I suggest waiting for the root to at least grow half an inch, or enough that you can place it in a jar and it can sit in water or be planted in soil.
Now that your avocado seeds has roots, you can choose to either keep growing them in water, or growing them in soil.
Personally, I enjoy seeing the roots grow in water, and once they are super long I go ahead and plant them in soil.
Once you have your avocado seeds in water, you can start to see the process of them growing their stems! I think they look so cute in these cute little jars. You can turn anything into a propagation station. I use small vases and jars, and shot glasses. I also love repurposing glass containers you have after finishing some food products. For example, used glass beverage bottles, condiment and food jars.
I recommend changing out the water in your jars when your water begins to look foggy, or when the water starts to get low.
The rest is up to you! You can keep them in water or eventually transition them into soil. I transition mine into soil once the stems get pretty long. Once they are in soil I move them outdoors and onto my patio where then get good indirect light. They are doing well so far, although I do admit I haven't been watering them as much as I should be.
It is best to water them when you see the soil is starting to dry out.
That's just my problem with outdoor plants, since I don't see them thorough the day, I tend to forget. Oops! Trying my best to get better at this! Nonetheless, I have been happy with their progress and I don't see myself ever not growing these babies!