I haven't really played Bard yet, but I can provide some general tips and show you my tentative layout.

Tips:
  • You can't use the d-pad and the left stick at the same time, which means you have to stop moving (momentarily) to activate skills slotted to the d-pad. I tend to keep most (important) weaponskills on ABXY buttons.
  • Try to keep all of your most-used skills on your first bar, and less-used/niche skills on additional bars.
  • Make use of extended bars (RT+LT or LT+RT), as they tend to be easier to access than toggling to manually switching bars.
  • You can also use the W-bars (double-tap RT or LT), but the double-tap requirement makes them a bit odd. You can set them for ABXY buttons only or both d-pad and ABXY. I tend to use them when I really need the extra slots.
  • Placing your most-most-used skills on the same trigger (e.g., RT ABXY and d-pad) can help reduce button presses.
  • Activate one of the standard (non-cross) hotbars for cooldowns you want to keep track of (skills you don't put on the primary bar). e.g., if you put Barrage on an extended bar, you can put the skill on this hotbar so you know when it's up.

In the end, though, the only way to build the layout right is to build it yourself. Everyone is going to have vastly different layouts.

Anyway, here's a document with my (tentative) layouts. It's somewhat self-explanatory. W is W-bars (double-tap) and Ex is extended (RT+LT or LT+RT). 1 and 2 are hotbars 1 and 2 (I can tap RB to swap between them). Purple squares in hotbar 2 copy whatever is slotted in hotbar 1. This also uses the alternate cross-bar layout, where the d-pad buttons are always left of center and ABXY are always right of center.