I'm not really a builder, but I do have fun building stuffs for my Sims and sometimes joining some challenges too.
1. Get a good reference - it can be from anywhere. Something that you can follow easily & modify accordingly.
2. Don't limit your creativity - it can be unrealistic, or it can be weird. But I would say, that is what we call unique & have its own identity.
3. Roofing can be so frustrating. I'm still learning too. But, you can start with a modern house first & get comfortable in building/renovate the exisiting houses/community lots.
4. Go small first then start expanding.
5. Play with the tools - it can be the terrain or the stairs. I hope that we could someday get a water tool soon.
6. Always test your build if you're planning to share it to the gallery.
7. The landscaping is important. You can build an amazing house, but the landscaping makes it more beautiful.
8. MOO is the best cheat!
9. Participate in building challenges. It will help you in terms of focusing on what to build for that particular challenge.
10. Be proud & don't compare your build with others. Your build is amazing & just getting more amazing as you build more houses.
I would say, this is my proudest build so far because of how I'm using the terrain tool. The house is pretty simple, but I had fun playing with the tool and getting my Sims to walk up along the pathway.
https://i.imgur.com/bfy9F4F.png
https://i.imgur.com/rPHOxCY.png
https://i.imgur.com/rCGrD5k.png
You can check out this build here,
The Hilltop House