Almost everything written about events is aimed at hosts. But most of us are guests far more often than we are hosts, and being a good guest is its own small skill. It is also, quietly, how you keep getting invited to things. Hosts remember who made their night easier and who made it harder.
RSVP, and mean it
The single most useful thing a guest can do is reply, and reply honestly. A host is trying to plan around a real number. A clear no is more useful than a vague maybe that becomes a silent no. If you know you cannot come, say so. If you genuinely do not know, maybe is fine, but do not use yes as a way to avoid the small discomfort of declining. The host is buying food and counting chairs based on what you tell them.
Show up close to when you said
For a casual party, a fashionably late half hour is normal and fine. For a dinner, a seated meal, or anything with a start that matters, arriving on time is a kindness. The host has timed things to land, and a table waiting on a late guest gets cold and awkward. If you are running late, a quick message lets the host decide whether to wait or start. The silence is the part that stings, not the lateness.
Bring something, even small
Unless the host has explicitly said bring nothing, arriving with something small is good manners. A bottle, something to share, a treat for later. It is not about the value, it is about not arriving entirely empty handed at someone who is spending money and effort on you. If there is a bring list on the event, check it, both so you contribute and so you do not duplicate what someone else has covered.
Help the room, not just yourself
Good guests do small things that lift the whole event. Talk to the person standing alone. Offer to grab drinks for the people near you. Do not let the host get stuck doing dishes alone at the end if you are still there. None of this is heavy lifting. It is just noticing that the night is a shared thing and contributing to it, rather than treating it as a service provided to you.
Say thanks, and mean that too
A short message the next day costs nothing and lands more than people expect. Hosting takes effort and a little nerve, and a host wondering whether the night went well is reassured by a genuine thanks, that was lovely. It is the smallest possible gesture and it is the one that gets you on the list for the next one.