You could try a little pond, nothing fancy, just a dip in the ground would do,few inches deep at most with graduated sides so that anything getting in there could also get out. The birds would like it as well.
Or, one of our neighbours has quite a deep container, probably a couple of feet high, just a flower pot shape it is and he has a miniature water lily in it and it looks great. I wouls also want to put a ramp on the side to help anything get out if it fell in!
I have never had one, or even seen one, but how about a low growing plant to have instead of grass. Chamomile? (Spelling?) Or you could pave an area, enough for a couple of chairs and a table. Crazy paving? Decking if you can get anything like that from your local Freegle maybe?
I have often used the seed that you can get, in a box, B&Q, Home Bargains and places like that sell them. They usually have a theme, eg bee friendly, or specific colour themed flowers etc. I have used them for the last few years and they work well and are very easy as far as looking after them goes. You would have to be quick though, we are in June already. The plants are just annuals, but some like poppies might seed themselves for another year, we have got fennel, both green and a bronze colour, orange and yellow poppies, growing from seed from last years plants. They are cheap to buy too. They are in a box and you tear off the side to find 4 or 5 holes, you rake the soil level and shake the box to release the seed. It is mixed with a little sawdust so you can see how much you have put down and where. Water it in and bob’s your proverbial! No covering the seed either.
Why can I never limit my messages? They seem to go on and on, sorry again.