Keep an Eye in the Sky
Senu's vision is even more helpful than it first appears. Not only does it reveal the terrain ahead and automatically hilight points of interest, it can also tag enemies, even through walls and ceilings. Moreover, those enemies stay tagged, allowing Bayek to keep tracking of every hostile in a given fortress or encampment. Senu's vison also spots crafting components and hidden treasures, and notes enemy motivations (an enemy with status set to 'Ambush,' is one to wathc out for). Any time you plan to attack more than two people, or any structure bigger than a coffee table, be sure to get Senu's eyes on it first.
Always Mind the Fiqs
Or drachmas, as the case may be. As it is, the lesson is to always loot the miscellaneous sacks, bags, vases, and boxes that are close to hand. Normally you'll get between 4-6 coins for your efforts, which doesn't seem like much, but every so often you'll get several hundred coins, or a legendary weapon. You don't have to be very close to container to loot it- you can even loot most things from horseback. So just remember to keep keying your pulse, and scooping up what's revealed.
Not Yet An Assassin
Bayek won't get the signature Hidden Blade weapon until the Aya quest in Alexandria. Until then, all his hand_to_hand stealth takedowns, including drops, are non lethal. These stunned enemies can be looted, but can't be dragged into the shadows, and don't get any of the XP bonuses that apply specifically to assassinations.