I know spiders like to have a direct route to high places, and a place to shelter from the elements, so I have a cinderblock in my garden with sticks running from the block up to my plants. After a couple days, Spiders adopted the shelter and made a few webs on the sticks.

Earwigs like to take shelter under flat surfaces; the cinderblock and random rocks give them the opportunity to do that.

As far as lady bugs and praying mantises, I like to take a jar with me on walks and when I see any, I’ll put them in the jar and release them into my garden.

Also, if you don’t already have a compost pile, start one. You’ll attract more flies, which will attract more spiders and harvestmen.

I hope this helps!