I had large froglet mortality on my artificial stone:
Froglets in mortal danger from pond edging.
My froglets are moving away from the pond naturally - I soon decided there was no point putting them back in the pond - they had other ideas
I have created alternative habitats - see thread, but what they like best is grass - I'm always stepping on them on the lawn. I have long grass areas near the pond - some are in there - but they soon get though the hedge and onto the lawn again. I mowed it recently and the grass is short, but they love it - they are so little they are covered by even short grass.
In dry weather I try and ensure the bog garden and long grass areas are sprayed with water regularly - to give them somewhere to retreat to.
I know will accidentally step on one or two before before the year is out.
But what can you do - you can only do your best.