Broken Tile Mosaic in Bathroom

Well, I finally decided to try my hand at some bathroom DIY and ripped out two layers of wall crap surrounding my tub. In the past, one layer had been 1950's pink plastic 'tile' with black plastic trim. It had yellowed in spots with age? exposure to glues/chemicals? No matter--it's gone now and I replaced it with some backer board, adding extra nails/screws since I'd bought the wrong thickness (on the advice of a tile pro!) + it was easier for me to load and carry.
Broken tile in tans, rusts and ochre made nice swirls with a 'slap it on and go' method. No more hours spent carefully arranging pieces. Whew. A few days later, I added some more items--completely random--some broken plates, beach pebbles, colors, metal parts and even 'brass'. I'll use some necklaces and shells too. I think just doing bits at a time will allow me to contemplate each area--I've rushed things before and ended up unhappy--so far I'm fairly pleased, but I want to keep 'flow' and 'movement' a constant. There's even a little frog face, fish, and crab for wee ones!