The great thing about "Newbie" GM levels is, you never have to keep them... They always convert to something else!
Even as a Newbie, I was a planner, and an "Adder". I always had to add something to the pot, some little touches that were wholly mine... I guess house rules figure into this, but usually I went the route of new spells and magic items.
Anyway, even as a Newbie I planned and added... Unfortunately, I quickly discovered that PCs always do something unexpected, and that the rules don't cover... If it is something one could attempt in real life (as opposed to leaping the 50' chasm to land upon the ledge, 10' up, on the other side), I saw no reason to say no, so I had to learn to wing it...
I have never been comfortable, as a winger, but eventually became good enough that entire adventures could be made from a pre-planned Random Encounter. In order to "Plan" my way out of winging, as much as possible, I have my "Pack of NPCs", on 3x5 cards, where I have, for example, "Rogue (Thief) 5", "Rogue (Con Artiste) 1", Ranger (Giant/Goblinoid/Orc Tracker) 7", "Barbarian (Tracker) 2", "Paladin (Rider/Healer) 2", etc.... So if I need a Thief to try to "acquire" an item from a seventh level party in the next town, I look through the "Rogue (Thief)" cards for a "7", and have his Pick Pockets/Sleight of Hand score all ready to go. The tables in the DMG, while not as specific, also make this easy... just copy the info onto a 3x5 card, and update the equipment!
So, I guess, now, I have converted all of my Newbie levels to Planner, added a little Winger, and increased my World Builder/Adder skills, a bit. I have always avoided Sadist and Railroader levels, and I think that I have gotten rid of all my Newbie levels, by now... I hope!
Planner: I plan on having fun!
Winger: I hope to have fun!
Sadist: Watch how I kill all the PCs, tonight! It's going to be so cool!
World Builder: The PCs are finally going to find out what they have to do, in order to escape The Forest of Fear, tonight! Boy, are they in for a surprise! I can't wait to see the look on their faces!
Railroad Engineer: We're done with The Forest of Fear, tonight, and we'll be starting up with the Mines of Morvia, next week. I hope Jerry doesn't start up with his Wizards wanting to do spell research, again!
Newbie: I don't know what we'll be doing, next week, yet. I just got the Soulless Citadel module, last week, but a couple of guys have already played in it, and it's all the way across the kingdom from where we are, now, and I don't know how to get them there!