My boy turned 3 in Feb this year, and he spends weekends with me since me and the mother have broken up.
Disclaimer: I havn't read all the literature out there on how to best parent but took a few pages out of my own upbringing (both good and bad). As a kid my parents were far from rich, so i didn't have a lot of toys and the one i had were often handed down to me.

On my Do-list:

- overwhelm my kids with all toys appropriate for the age (+1 year) but supervise him when playing with them. I keep giving him things until we don't have any more room for toys and then force him to pick out stuff he no longer want, which we give to less fortunate kids. Teaching him empathy at a early stage seems appropriate to me.

- Teach him that everything can be modified. I bought him a ride-on car that we progressively have modified with proper tires, disc-brakes, carbon fiber spoilers and details, wrapping. He loves his car, and have developed a love for vehicles. He can now name most common and some exclusive cars as we walk down the streets. He can also spot the difference between steel, aluminum, brass and his interest in powertools have caused me to buy kid versions of many of the tools we commonly use when we rebuild his car.

- I got him Duplo that he loves (trains, cars and generic blocks). People will downvote me for this but I reached out on facebook for Lego a month ago and we received a lot. I've explained that if i ever see a piece in or near his mouth i suspend his right to play with it for the duration of the weekend, and since he is with me only on the weekend i keep an eye on him every second. So far, so good. At this point he is building and adding to stuff we build together and i see clear improvements in his ability to place even the smaller parts every week. Initially he kept asking me to put pieces together as soon as it didn't work the first time but now he tries 6-7 times before i have to pry it out of his hands to do it for him :)

- i tried to explain our solarsystem and he is showing extreme interest in videos about space, rockets, moon/space walks so it's become a small tradition that i replay SpaceX latest achievements and failures when there is any news.

- I have avoided only selecting toys/areas of interest/gender-based toys and try to give him everything from musical instruments, balls, frisbees, toy-kitchen, dolls. Whatever he chooses to play with and show interest in, he gets to do.

- music-wise i expose him to everything from classical music, rock, hiphop, children music to break-core and classic EBM/EDM. Lucky for me he sidetracked into EDM, so to sponsor this interest in dance music i got some vintage synths, sequencers and drum-machines he loves to play with next to his acoustic instruments.

My Don't-list is short and basically just contains stuff i don't want him to see when he has screen-time:

- i try to avoid the most brain-dead stuff, like repetitive viewing of the same videos. Videos about counting and colors are all good stuff but at the point when he knows it, it makes little sense to show it to him again, and i try to find interesting videos that drives a conversation about what we are watching, as we are watching. I avoid endless playlists and allow him to tell me what he wants to see, as i help him search for appropriate videos.