Coordinates can always work, but I hope this will make things easier: relative hex reference. You can ask me to mark any hex with any symbol, and I'll update the map. Abbreviations, shapes, and number are all valid, and also colors.
Starting point: green dot in the white hex
The grey hexes are north and south of the start, so the blue triangle is S2 from it, the black triangle is S3 from it, and the red triangle is S3E1 or S2SE1 from it.
Horizontally it's easy: cyan dot is W3, the black dot is E2, orange dot is W2S1.
The red square is NW2, the green square is NE3, while the blue square is NE2E1.
Starting point: black dot
The blue square is N2, green square is N3, red triangle is SW3, blue triangle is SW2W1, black triangle is SW3W1.