Any advice on how to be an interesting GM?

The first and most important thing to remember about being a GM is that the game depends on you. If you are active, participating, and trying to tell a good story the players will typically go along with it, but if you start falling down on the job and not posting the game will die.

Hope that helps.

Connected to that is run something you not only enjoy but can maintain energy for until it is finished

Hm, read books, watch anime ect. One good tip is run a system you know, some planning in advance can help too.

Do everything you can to keep the story/game moving.

That may mean prompting the players for their actions or NPCing characters when players go silent for too long. How long? A week or two during narrative sections, maybe just 24 hours during action segments.

Do your best to make your posts vibrant and evocative.

Characters shouldn't just enter a room as though it's a blank box. They should enter a particular space that you envision for them. Is the room dim, dark, blazing with candles? Is the floor marble or granite or spongy wood or plushly carpetted? Does it smell of lilacs and lilies or is it musty and rank? Are there many tall windows draped in velvet curtains or a single, small, naked opening high in the wall admitting a single ray of wan light.

Say 'yes' to your players as much as possible. When one says 'I snatch up the poker by the fireplace and smash the monster in the jaw!' you give it to her if you possibly can and roll with it. Reward player creativity; add it to your own.

Accept the fact that no matter how you do it, it is not going to be 'right' for everyone.  There's nothing wrong with that...it's human nature, we're all individuals and as such, our individual tastes and traits do not always mesh successfully with others around us.  Do what seems right to you, players who like the way you run it will stick with you.

Keep in mind that this is a hobby.  It's supposed to be fun, or at least enjoyable on some level (horror stories aren't something I can really call 'fun'...but they can be enjoyable).  That means it should be fun for you, as well as the players.  If it stops feeling fun, figure out why and fix it.

Don't be a slave to the rule book.  Odds are really good that at some point, some or all of your players are going to come up with something that the rules don't address really well, or they'll make a good argument for why the way the rules handle it is wrong.  Be willing to flex a little bit...but be consistent.  If you let Player A delay the blast on a fireball once, he's gonna want to do it again sometime...

Understand that "No combat plan survives first contact with the enemy".

Be flexible. Allow your players to win more often than not. But be consistent more than that. Be religiously consistent. The players have to believe that it is them against the system, against the game, against the environment ... NOT against YOU !

As soon as you make it personable, they will disappear.

Also POST. Post frequently and post often. The post some more. If the players perceive that you have lost interest, why should THEY hang around ? Especially when they believe that you have better things to do than to see to their needs.