The first thing I do when I get to a new world is scope it out. This hearkens back to the time when you used to have to activate the teleporters before you could use them.
1. Talk to every NPC & pick up any Zeke and book quests because you'll come across a lot of the items/books you need in a dungeon or boss fight.
2. Don't automatically do all the mob/collect/defeat quests first. Stack what you can because more often than not you'll run into those mob creatures during a boss fight and you'll get credit for that quest.
3. To maximize your pet/gardening energy, take care of your plants before you do anything else. This way your energy will be filling up while you quest, do daily assignments, PvP, etc. You can then either train your pet or top off your garden before you log off (your energy will refill while logged out).
4. When you level up: Take a few minutes to deplete your energy by training a pet. This way it will fill up when you begin questing again. Also if you know you are going to reach a fifth or tenth level, be prepared by having gear you plan on upgrading to at the ready.
5. If you are at max gold you can buy reagents or pet snacks that you WILL most likely use instead of just throwing the gold away.
6. I find it helpful when dual/triple/quad boxing or questing with friends to triangulate my/our wizards so they can port to each other. This saves so much time on getting back and forth and much less risk of getting pulled into an unnecessary battle.
7. Utilize your gear and deck set up. Take the time at the beginning to set up assigned outfits and decks for your wizard. I usually have 4: Main set up for mobs, (My School) Main set up for mobs that are the same class as my school, Boss set up, (My School) Boss set up. The set ups for mobs and bosses of my school have my prisms.
8. Know how to create a small deck so you aren't spending a lot of time in battle trying to draw the card you need. Once you get your school's AOE spells, your deck should only have 2-3 of those & 2-3 blades. Add any Sun spells once you've trained them.
BaileyJade on Wizard101Central had started a thread like this for others who wish to know more helpful tips that haven't or can't post to this forum
PS I just read about the one tip per account limit OOPS
I think the most important thing to do is to ALWAYS be prepared. I think what annoys a lot of players that put in work to become strong are always finding wizards with underwhelming gear that hinders the progress of questing.
I prepared a list of hotspots that wizards SHOULD go to at lv 30, 60, and 100 to get gear that reduces your chances as much as possible from dying. Trust me, strong gear helps you pass through the worlds like a breeze. Most experienced players would know about these places, but for players that don't, well here they are.
Lv 30: Mount Olympus Lv 60: Waterworks (and/or) House of Scales Lv 100: Darkmoor, Krokopatra Exalted Duel, Rattlebones Exalted Duel
I should also mention that the Professor Hoard Pack has excellent boots and wands for your level and is always more superior until roughly around the start to middle of Arc 2 in that case there are a few other packs or bundle like the Witch Hunter's Bundle and the Terror Hoard Pack.
At lv 50-59, Celestia doesn't have bad gear and surpasses Mount Olympus gear. They can easily be found in the bazaar. Craftable ones though are the strongest in that level range.
Speaking of crafting, this is also extremely important because if you don't want to buy the hoard packs or farm from Waterworks or House of Scales, some equipment that can be crafted are excellent. The max level boots in Empyrea are something worth crafting (Part 2 ). Also, the craftable wands in the Arcanum is another option to explore. They aren't weak, that's for sure. This tip is for damage.
If you are looking for resist, you would need Jade Gear that is given from the Keeper's Hoard Pack. Mainly Life or Ice wizards would be using this since they are excellent tanks in the game. Usually this build is to heal and if so, some wizards prefer gear with high outgoing and those can be found in the Ninja Lore Pack or the Jewel Crafter Pack.