Every new level comes with new practices and trains. These should be put into skills/stats/health as soon as is available. Good players generally save few unspent practices and know what to do with their new ones before they even get them. It is wise to save a few for contingencies.
The most effective way of staying alive is to run away from fights. Players can move fast and should have no difficulty escaping unless hindered by a spell or skill (including lag from their own skills).
Run circles around the area to tire out your opponent and waste his consumables (potions, scrolls, food). If he persists in chasing, you can even run all the way across the world. Eventually he will lose the trail and you will be able to return to your guildhall.
Using aliases can save a lot of time typing. e.g. "alias 1 drink barrel"
You can store up to 10 aliases in-game, or more if your MUD client supports
its own aliasing. It also pays to use things like 'di dan' instead of
'dirt danarubin', when you are fighting players.
Your health will change to yellow and then to red to indicate its a really good time to run away. Keeping an eye on your health and on how much mana and stamina you have left (or any other things you have put in prompt, like combat styles) should be a part of your playing.