Tiles - Mixing, seamless or otherwise?

So, in this thread (https://forum.unity.com/threads/hexagon-or-squares-what-to-go-for-in-maps.550258/#post-3680020) I talked about the choice of tiles, I choose hexes. Then I build a world generator and that generates a world like this;



You can see the edges of two land masses and a small island between them. Now, I want to make it look better. More specifically I'd like to blend the different terrain types somewhat. If you take a look at Civ V, it looks like this.


The different tiles kind of smooth over each other. I can sort of think ways to do that. But am not entirely to sure how. I've read about height mapping, texture scattering, texture splatting etc. But not much in the way of practical tips or advice.

So, here is the case; I have a procedurally generated map in hexagons. Each tile is either ocean, deep ocean, land or strand. I'd like to have a way to smoothly visually transition from one type of terrain to another. Anyone have good idea on how to that?