Aside from the obvious good desk, chair and monitor(s).
I like a laptop, so a good dock is really nice to move between desk with full desktop experience and couch for more relaxed work.
Good headset or speakers+mic. Make sure the audio on calls is good. Especially if there’s noise around you really good headphones help so much. Sets with a good mic are harder to find. My QC35s were amazing but the mic picked up noise across the room. Noise cancellation meant I couldn’t hear the TV or family next door, but others on the call heard it very clearly. A good office headset like a Jabra works well here. A separate desk speakerphone unit can work really well here too.
Monitor mounts make a pretty big difference in terms of desk space and being able to reposition when sitting or standing.
I love my standing desk, but I found both the foot hammock and balance board to be amazing additions at relatively low cost for how much I love them.
A good webcam at a nice angle can be great compared to the laptop ones. It’s a lot more flattering and adjustable.
Get a mix of room lighting. A good room uplighter, ceiling dimmer, desk lamp, etc. having a mix allows you to feel a lot brighter and more active, or dimmed with a spot and focused, or generally dimmer and relaxed. Basically the opposite of very standard flat bright office tube lighting.
I really like my iPad Pro in addition to my laptop. It feels far more mobile, and is easier to task switch on for things like Slack, email, etc. with an MPB it’s a funky little extra screen too. It’s the first thing I grab when I just need email/slack updates, or when I need to go through docs and don’t want a full laptop. With the Magic Keyboard it’s usable and I’m always surprised how nice it is.