Rules for Combinations (HTRYC 3rd)

"If these factors do not exist, then a combination cannot exist either.  At least one of these factors must be present if a combination is to work"

1. Open or weakened King.  Also includes Stalemated King
2. Undefended pieces (this does not include pawns)
3. Inadequately defended pieces

Only look for a combo when one or more of these appear.  If they do not, then don't look for a combo.