I love these tools n' things:
If you're like me and you struggle with rolling out dough evenly, invest in a rolling pin with guides. You can set it to 1/8 or 1/4 inch and your pie dough worries (at least some of them) are gone! Amazing.
Buy yourself a kitchen scale and start weighing things in grams as much as your recipes permit. It's so much easier and precise. I like this scale.
My counters aren't the best for rolling out doughs. I purchased one of these and never looked back. They make it so easy to roll your discs into a specific size and help you keep the round pie shape. I have one like this.
Ice cream scoops! Buy a few! For ice cream of course but even better, for scooping cookies, muffins, cupcakes and more. I have some from Volrath that I love and use constantly.
Invest in these silicone pie edge cover thingies. I heard they are amazing but haven't used mine yet. I can't wait though! Update, they are in fact, amazing!
I dig these 9-inch Pyrex pie plates.
Please buy an oven thermometer. Oven temperatures can vary greatly. Yours could be off by so much that it greatly affects the end result. It's a huge bummer when you put all of this time and effort into something and the thing that makes it all go wrong is your oven. Here's one from Taylor Classics that works well.
Speaking of thermometers, if you are really serious about cooking and baking AND have some extra cash lying around, get yourself one of these!
They are one of the best on the market and very durable and precise.