Well, it may be a bit early to actually start baking- though the freezer can be your friend- but you can certainly start planning.
The grocery stores are starting the sales on baking supplies, so it’s a good time (and budget-friendly) to spread the purchases out by picking them up over time.
Make a list of what you would like to bake. Figure out which special ingredients you will need. Chocolate chips? Coconut? Nuts? Cherries? Watch for those sales.
It’s also a good idea to create a spot in the pantry for those baking items. If you are feeling really ambitious, clear some space for the containers full of your delicious baking. Keeping them in the cupboard or the freezer, rather than sitting on the counter, removes some of the temptation, and gives you a better chance of having some left when Christmas comes.