1. Think BIG. Huge, even. You know how they say don't sweat the small stuff? Because it doesn't matter. Big stuff matters. It feels important and makes you look like you were important. It is also harder to hide and/or more likely to be found by people later in history even if some enemy or earthquake messes around with it in the meantime. The Karnak temple in Luxor covers two square kms, and was linked to the Luxor temple by a 3km avenue lined on both sides with sphinxes. Probably you could have seen it from space back in the day.
We saw Tutankhamen's mummy, displayed in his tomb in the Valley of the Kings (discovered by Howard Carter in 1922), and Ahmose I and what they think is Ramses I. Interestingly, the Ramses I mummy used to be held in a small museum in Niagara Falls, Canada (near where my dad grew up) until the late 1990s, when someone recognized the signs of potential royalty. After some research at a museum in Atlanta, the mummy was returned to Egypt in 2003. So you could say he's the Canadian mummy.
You aren't allowed to take photos in either of these places, so the images below come from the internet.
Pharaohs usually claimed to be descended directly from the gods, and since the gods were known to be immortal, that boosted their claims also. Maybe that did help with preservation over all the centuries. The murals below showing Pharaos making offerings to the gods are all over 3500 years old. I guess someone was happy with the offerings.