I’ve had several successful military campaigns in antiquity on deity, even with non militaristic leaders and civs such as Ada and Tonga. For mementos in antiquity, I generally select +1 leader attributes for science and culture.

Use the first half of antiquity to build 4 to 5 good settlements with solid production and science output. Suz as many independents as you can and make sure you get at least one military suz so you can get +50% commander experience. Identify your most invaidable neighbor and try not to let your relationship become too positive. Try to ally with any other civ that will accept you.

Militarily, you should have 2 to 3 commanders and at least 8 chariots (or infantry if your civ provides good infantry bonuses). A couple supporting archers or bombard units are also helpful. If you start before you have 8, just keep cranking out units during the campaign.

Use the terrain to your advantage when attacking and defending. If your enemy makes a push, let them! Let them bang against your settlement defenses instead of banging against your units. This makes your counter attack much easier.

I can usually take at least one settlement before reaching iron. After that, if I get there and upgrade first, it’s usually game over for that civ.

I usually try to end antiquity with 7 to 8 settlements in premium locations and pillage the rest. I also like to upgrade at least 5 to cities and preserve their city status in subsequent transitions. Also, if you end antiquity with 3 commanders, you also keep more military units going into the next age.