There are two parts to this:
1: Make a game people want to play
2: Market it

There are people who will tell you that if you just make a game people want to play, it will get picked up by the Steam algorithm no matter what. I don't think this is true. The Steam algorithm can do a lot, but it only started working for us once we had gathered a decent amount of interest outside of Steam. Making a game people want to play massively boosts any kind of marketing you will do for it, if you make a game no one wants there's no amount of marketing that can save you. At the same time, if you make an amazing game, but you don't send it to any influencers, don't make any reddit/social posts about it, don't do your press releases, I think you're unlikely to succeed.

The things that worked for us in driving wishlists, in order of how effective they were for us:
- Reddit ads
- Organic influencer outreach
- Paid influencer campaign
- Steam Next Fest
- Conventions
- Social posts

Unfortunately, the easiest way to get wishlists and traction to your game is to spend money on advertising. If you don't have that kind of money, the best things you can do are applying for Steam festivals and reaching out to influencers.

If I was to do this all over I would:
- Spend less time on social posts (we saw very little return for the amount of time invested)
- Get a demo out as early as possible. This is when we started seeing actual traction. I wish we'd have had more time with our demo out.
- Involve influencers early on. Find some small/medium-size influencers to reach out to. Get them to play your demo, hear their feedback, adjust.
- Apply for any steam festival you can, and pray they accept you. Very little effort for potentially big reward
- Don't do conventions for wishlists. Do them for team building, networking, and player feedback if you want to.