We know that Sam sailed west in F.O. 61. Cirdan sailed west in the last ship he had made at the Grey Havens. Celeborn sailed west sometime after Cirdan, but it is undocumented whether Elladan and Elrohir accompanied him (I assume they did). Legolas and Gimli took their own ship after Aragorn's death in F.O. 120.

So, any thoughts on the Timeline? All we know is that Sam went west before Legolas and Gimli, and Cirdan went west before Celeborn (with the twins or not).