HT Games
Hidden Orbs
In the first level, do no neglect the lovely ladies waiting for you on a bed after you beat the Hydra. Get into bed with them and press "Circle" to initiate a minigame that will reward you with a cache of red orbs, good for leveling up weapons.
Tons of XP
You have the opportunity to amass a large amount of experience (XP) early in the game. When you first receive Medusa's Gaze, skip the tutorial and instead use Poseidon's Rage. Since you are in a "training room" of sorts intended for you to learn Medusa's gaze, you will have infinite magic and can keep using that attack over and over again. The enemies will keep respawning, and if you use Poseidon's Rage, you will accumulate large combos and lots of XP. Use this XP to max out Kratos's abilities.
Move Faster
If you would like to move much faster than Kratos is usually capable of, you can combine a roll with Hermes Rush. Press the right analog stick forward to initiate a quick roll in the direction that you wish to go, and then press "R1" to execute a Hermes Rush shoulder charge once you have unlocked that ability. This will allow Kratos to roll and charge very quickly and move at a fast rate.
Skip Pandora's Box Conveyor Belt
One of the trickiest parts of the game is the conveyor belt area on the Pandora's Box level. This level has you fight harpies and arrow-shooting enemies as you move through a conveyor belt with hidden death traps. To avoid fighting all of the enemies found here, walk as far as you can to the left or right of the entrance without running onto a conveyor belt. Jump onto the first pedestal and you should be able to move through the level without fighting any enemies. Hitting a conveyor belt will trigger the enemy spawn, so it may take a couple practice tries to get it right.