DO

• Double click on edge loops and add deformation
• Extrude - Grow your mesh
• Scale
• Delete Construction History - Delete history often to prevent software slowing down and increase file size

DONT

• Use non Manifold Geometry - When two or more polygons cannot be unfolded to lie on a flat place without overlappping. Can cause problem when when exporting or rendering
• Non-Planar Geometry - When not all vertices are on the same surface plane, this could cause error when exporting and rendering
• Subdivide too early - Avoid adding too much detail, use preview smoothing before doing a final resolution. Subdividing will make UV mapping or character rigging unmanageable

Topology - The characteristics of a geometric surface on a 3d object, the flow and organisation of edges in a 3d model.

Good Topology:

1. Deforms naturally and therefore animates well
2. Renders correctly in real-time
3. Has efficient distribution of polygons
4. Has Discreet and well placed seams for UV mapping

Good and clean Topology :

1. Has Quads and no Ngons or limited tris
2. Edge loops follows anatomy
3. Polygons are efficiently distributed with more detail where deformation occurs most

Bad Topology

1. Won't animate correctly
2. Won't deform correctly
3. Textures will look bad
4. Affect rendering
5. Hard to work with