Step 1: Choose a puzzle from the stack your mom gave you the last time you went to see her. Feel a little guilty because you probably shouldn't have seen her at all, but you have to balance emotional support with physical precautions right now. It's a delicate balance, but neither of you is showing symptoms, you are both cautious in the outside world, and your town has very low numbers so far, so you should be okay.
Step 2: If the box has been previously unopened, slit the edges very carefully with a knife or pair of scissors. Now is not the time for an emergency trip to the hospital! Remove the lid and start to get a little excited about all the tiny coloured bits contained therein.
Step 3: In all likelihood, the pieces are contained in a clear plastic bag. Follow the instructions above re: opening the bag. Make sure you get every piece out, remembering that time you were missing a piece and it ended up still being in the plastic bag in the garbage can. When dude reminds you to check the bag, scoff at him because what kind of dingdong are you that you don't learn from your mistakes? Miss a single piece anyway.
Step 4: Separate the edge pieces from the rest of the puzzle pieces. This means physically touching each of the 1000 pieces (or, if you are lucky, 1500, because, let's face it, 1000-piece puzzles are no match for your superior puzzling skills). This process is an effective introduction to the kind of pieces you will be dealing with. Are they regularly shaped pieces with the kind of edges that line up? Or are they "bits and pieces," the kind with fucked up little shapes that don't look like they should go together at all? Is this the kind of puzzle with pieces that have straight lines that look like they could be border pieces but aren't? Shit's getting exciting!
Step 5: Put together the border. Depending on the puzzle, separate the edge pieces by shape (pieces with innies on both ends, pieces with outies on both ends, and pieces with one innie and one outie) or colour, whatever makes it easiest to accomplish this task. You will inevitably have missed identifying at least one border piece while completing Step 4. Make no mistake, this is a moral failure on your part. You had one fucking job, find the border pieces, and you couldn't even do that properly. Jesus Christ.
Step 6: Allow the border to remain incomplete. Someone will find that piece eventually (unless it's still in the plastic bag, now buried under banana peels and moldy bread crusts in the garbage can).
Step 7: Start with the easy parts, words and small uniquely-coloured sections. Dude will probably get to these before you can, because he's like that. Accept this fact and start hoarding pieces for larger uniquely-coloured sections before he can get to them. Anything that runs the length of the puzzle is another good place to start (the top of a mountain range, a fence, a roofline, the water's edge). Although more challenging than the small parts, a similar sense of accomplishment can be achieved by connecting pieces from one end to the other.
Step 8: Once the fun parts are done, do the rest of the goddamn puzzle. Unless this puzzle is of the pick-it-and-stick-it* variety, completing the remainder of the puzzle is more of a chore than entertainment.
*The kind of puzzle where you pick up a random piece, find its placement using the picture on the box, and stick it where it belongs. This kind of puzzle takes, like, 4 hours max. Although certainly less fun, non-pick-it-and-stick-its (landscapes with lots of trees and an inordinate amount of sky with few clouds, possibly some reflections, or puzzles in only black and white) will take significantly longer to complete, and isn't that why you're doing jigsaw puzzles in the first place, as a way to kill time until you can meet your friends for lunch again? Alternating a pick-it-and-stick-it with a non-pick-it-and-stick-it is a good strategy to maintain your sanity during this difficult puzzling (both senses) time.
Step 9: You will eventually run into the crap part of the puzzle where the most effective strategy is to arrange the pieces by shape. So what are you waiting for? Arrange those pieces by shape already. (Honestly, you love this part. Your house is so organized already that this process brings you great joy. Creating order from chaos is infinitely rewarding, even if it is only puzzle pieces.) Once you do this, you will have to systematically try each piece of a certain shape into each remaining hole in the puzzle. This is admittedly kind of a drag, but the feeling of joy when you find one is unrivalled.
Step 10: When you are down to the last remaining piece (assuming it isn't still in the plastic bag or somewhere on the floor, in which case see Step 10B), put a single finger on it. Get dude to also place a single finger on the piece. Together, gently slide the piece into place, thereby completing the tableau.
Step 10B: Find the missing piece. It's probably still in the bag, because you are an overly confident dingdong.
Step 11: High five.
Step 12. Take a photograph as evidence of all the time you've wasted when you could have been doing something more valuable for the world, but then remember that this is doing something valuable for the world because you aren't outside spreading COVID-19.
Step 13. Leave the finished puzzle on the table for a couple of days. Relish your accomplishment. Fondly remember finding the piece with the cat's face (although dude probably found it before you).
Step 14: Grudgingly take the puzzle apart, making a half-assed effort to separate the pieces for the person who does it after you.
Step 15: Repeat Steps 1 through 14.
Step 16: Stay safe, and riot on.