See Texture Baking#Triangulation, and Polygon Count#Polygons Vs.Make sure there's enough room between UVs for good edge padding to prevent color bleeding between the UVs.Making sense of hard edges, uvs, normal maps and vertex counts, and Earthquake on separating smoothing groups in the UV.

For tangent-space normal mapping, split the UVs for every hard edge (where vertex normals are split, or different smoothing groups are used, same thing).Create good Texture Coordinates for your low-poly model.

See Normal_Map_Modeling#Low-Poly_Mesh and Understanding averaged normals and ray projection/Who put waviness in my normal map? and Skew you buddy! Making sense of skewed normal map details.

Remove details from the base version of the high-poly model, or use ReTopologyModeling.

High-quality bakes require specific modeling techniques, see Normal Map Modeling.

Build the source for your normal map, using DigitalSculpting and/or Subdivision Surface Modeling.

Test with all the required functionality so you can determine how much detail is required.

Create a rough low- to medium-resolution model, and get it into the game.

The baking workflow varies for each artist this is a summary of common baking tasks.

3ds max render to texture