how best to clean up a mesh

hello, i often end up with a messy mesh and/or several tris in my meshes, and this complicates matters when i subdivide or shade smooth, among other issues. What are the best ways to clean up your meshes and to avoid such problems in the first place?

You have to think like before… when you are doing the modeling. To avoid triangles…! after all the best way to clean mesh is do it manualy.

doing everything by hand.

with the new bmesh addon you can use ngons which are probably the best way to keep your mesh simple and good looking, but you should had used the ngons from the start.