Tips:

1. Nymphs in mission stages have unlimited stamina, and most stages have unlimited time. I maxed out the 'Eco-Dildo' tree by just harvesting and mass merging fruits/veggies until I got to the chili pepper at the end of the chain. Takes forever, but now I never have any further need for produce.

2. The fact that nymphs auto-harvest is annoying. Try to move them off if you hear the harvesting sound and you didn't direct them to do anything.

3. Some things you will want to pay to bring back to your home are rubies (yeah, pay one to get one) to combine for that tree, coronets for combining, and at least one golem scarecrow to generate boob padlocks that combine into safes. Although you do uncover golem wrecks on your land, it doesn't come till too late in my opinion. The scarecrow also periodically generates ink spots on its own.

4. Keep the area around your brothels free if you want the panties/bras. They only generate in directly adjacent squares. On the other hand, if you're trying to keep land free for other projects, clump all your brothels together and block off the adjacent spaces with other items.

5. Don't forget that merging 5 also works for shells/nymphs.

6. The end of some merge chains have purple highlights in the discoveries section. I haven't reached any of them yet, but they have to be more significant than the ones that don't...maybe an epic reward or something.

7. Save your bubbles for when you have land to heal. Stack them up outside your play area until you need them. You can also save mission rewards that way so they don't take up any land space until you're ready to merge them.

8. You will at some point need lower-level items that you can't harvest once you merge the thing that generates it too high. Either keep one of each low-level generators or be prepared to buy them as needed.

9. Don't lose track of time. This game is an enormous time suck which is a good thing, but damn if you don't start noticing the time at 4 am.