1. Have you got an AA credit card? if not, get one and charge things you would ordinarily buy anyway - groceries, utilities, even estimated taxes.
2. Aadvantageeshopping.com. At the moment giftcards.com is offering 3 miles/dollar. Be sure to go through chrome. I think the code holidayvisa or "visaholiday" gets you $10 off a $100 gift card which will be emailed to you. It will be slow going, but you can order these and keep a document (mine are in One Note) listing the numbers on these cards. There are some catches to them though, primarily that they are only good for shopping/paying online and not in person, you can't do a split payment with them and you can't go over (e.g. with a regular store gift card for $100, if you spend $120 the gift card will automatically credit $100 and then you have to come up with $20 some other way; with these you are limited to a charge of $100--if you charge $101 the card will bounce). However, you can rack up a lot of miles fast with these if you save them to use later. Be sure to carefully read the conditions, and be prepared to email AAdvantageeshopping & fight for your miles if necessary, I have had to repeatedly. But I've gotten a LOT of miles!
3. Bookaahotels.com and look for Aadvantage miles to be shown in the banner. You can get lots of miles that way too. Your stay has to be completed by 2/28/2023.
4. Various other hotel earning programs where you specify your credit should be Aadvantage miles.