Teleport is vital. Multihome helps. Grief will happen; be prepared for it. Learn who has investigator and water (new players like to build their own farms if there isn't one available). Cash upfront, many players don't last more than a day. Be ready to coach players on /vote. Stress using /sethome and /home; they don't need to ask you for teleports then. Sell cheap food near the plots and have a public enderchest for use. NO mining in town. Inform them of /warp mining and the exp benefits. Set a max depth and height for builds. I'm sure there is more, but I will leave that to other players to mention.

 

Give people a reason to live in your town, wether thats living in a beautiful town, or a highly functional town (EG. Public farms is a big one, fishing tables, shops, etc). You can have a balanced mix of both which is usually fantastic.

Also, take what LJ said on board. Practically all of that is essential details to address.

 

Your town should be a safe haven for people to live in while still offering amenities such as farms, and fishing towers. It should be actively changing, whether it's adding new amenities or just making a concept so that your residents won't get bored!

 

It really depends on if you want a community or you want money.

If you want money, many layers of small plots... Message the builders who look for towns and invite them there. Charge nstars because they can be available via /voting.

If you want a community then focus on aesthetics, make the town look nice, try to only invite those people who seem like they will be around for a while. Charge rent even (Monthly, 1-3 nstars) just to keep people active and in your town. Offer free services, public farms, welcoming gifts if they last 3 days or something (Diamond tools and iron armour, etc.) Stuff like that :)

 

One thing I've noticed that helps (on top of what everyone else has said) is aesthetic appeal. Add in a few things that have no real use but look nice. A park, a church, statues, random buildings, things that people don't really have much use for but that look pretty neat. It doesn't seem practical but if you look at some of the more successful towns on the server, you'll notice they're abundant with useless structures.

 

My biggest failure was being disorganized. My first town was the perfect example. I allowed users to buy, say, a 100×20 plot in the middle of town. DO NOT DO THIS!
I would highly recommend setting up plot spaces, before you sell even. This will keep your town attractive, neat, and massive sky-high-100×20-tower-of-cobble free!

Another quick marketing tip... Hang out around spawn. A lot of new plaers will ask almost immediately upon joining to get land. Watching local is important, as you can trade their nstars from voting for a starter 10×10 (3 nstars for a 10×10 is nearly 80% above average cost)