question about tuning with timing

Typically when tuning for max hp does one add a little bit of timing at a time until no noticable gains are acheived? From what i have gathered this seems right, as one starts adding a little too much the egt's start rising rapidly then detnation will occur.

So when i go into it I planed giving it a point at a time until no big gain is acheived then stop there and back it to the point where the last big gain was present. Does this seem like the logical way to tune a timing curve?:)