Depends what you want your guild to be. PvP Guild? Make sure you have PvP events for Cyro, BGs, IC etc. PvE Guild? Have dungeon/trial events. I like guilds that do PvE mainly because I only really play BGs, but that's due to my preference. If you create a guild that appeals to one type of preference you'll likely get some people to join.

Guilds that are active have the following:
- a discord (doesn't have to be mandatory)
- do stuff together: pick-up pledges, scheduled events, farm runs, housing
- conversation

IMO in a guild of 400, most guilds have 3 categories of people:
Category 1: about ~20 people who are very talkative, active, and participatory
Category 2: maybe 50-200 who are somewhat talkative and participatory (or participate mostly when they need help or are prompted)
Category 3: the rest are usually silent members or completely inactive (some people just take a while to get involved or are shy in big group settings)

Of the 5 guilds I'm in, I'm only category 1 in one or two of them.

Now, these are two things that EVERY player needs at least ONE guild with, but your guild doesn't need to have:

- a guild hall with all crafting stations
- a guild hall with parse dummies
- a consistent guild trader

It's a really good idea to personally message your members to invite them to do group activities, or just ask if they want to do them—it breaks the ice. Some guilds I've been in I've NEVER spoken to a GM or officer, and that def makes me less active (not their fault, just saying)

A reason for like-minded players to join.

That can be almost anything, the important thing is it's clear to you and you can make it clear to potential members when advertising, and that it's actually true. That last one might seem obvious but a lot of guild leaders/recruiters will say whatever you get people to join, then act confused when they leave because it doesn't hold up. Like a guild advertised as doing both PvE and PvP where actually all the activities are PvE, because the leader assumed that probably once there's enough people some of them would be PvP players and they'd probably do stuff together but never did anything to make that happen.

I think it's worth remembering that you probably don't want everyone in ESO to join your guild, or even to consider joining. You want the right people for your guild, so it's ok if your reason to join will also put some people off. Think trade guilds with minimum sales quotas, trial guilds which require specific builds to join, casual guilds who require their members to be on Discord or to talk in guild chat sometimes or remove people who are offline too long etc.

There's thousands of generic, interchangeable "friendly helpful PvX guild open to everyone with a guild hall and sometimes a trader" in the game already. And while there's nothing wrong with that (as long as it's true) it also means your members could leave at a moments notice and find another equally good guild within minutes, so building loyalty is going to be difficult.

So my advice is think about what you want from a guild. What does your ideal guild look like? Why are you starting your own instead of joining another? What have you been unable to get from other guilds which makes that necessary? That's your starting point.

And like I said it can be anything. One of my guilds is, on the surface, one of those generic friendly casual PvX guilds. What made me want to join is their recruitment message genuinely made me laugh out loud and let me know this is a very laid back group of people who do not take the game seriously. They're always chatting in the guild channel in game, always willing to help anyone out with anything and unless you're joining the progression group for trials they're not fussed about builds or anything. I can genuinely say "who wants to do a random dungeon with my terrible, low level sorc I haven't played in ages?" and people will join. We'll skip or fight as we (as a whole group) feel like it, spend time looking around the dungeon, get lost and double back...but we have fun doing it.

And like I said I'm sure that would put some people off, I bet some people on this forum would read that and think it sounds like an absolute nightmare and not worth wasting their time on. And that's ok, it just means it's not the right guild for them.