We are very fortunate at Flatford to have the space for quite a large garden pond. We were already seeing pond plants sprouting with new green shoots and insects hovering around the water on the warmer days in March before the garden had to close.
Even without a trip to the garden centre, it could be possible to create a small pond in your own garden using either an old plastic or metal bucket or tub, plastic pots or seed trays (without holes of course) or even any large unused ceramic bowls from the kitchen.
The vessel can either be standing on the ground or sunk into the earth. If it's above ground, there will need to be bricks, logs and or plant pots in varying heights around it to enable wildlife to climb in and out safely.
Even some folded up water-tight plastic sheeting can be laid over a shallow hole covered in some soft sand to make an invaluable watering hole. Equally, whether it's standing or sunk into the ground, put bricks and/or stones in one side to give wildlife easy access in and out of the water.
Even a simple watertight seed tray filled with stones to create just 1cm depth of water is a valuable place to drink for butterflies, hedgehogs and birds and frogs. Dragonflies and frogs could also soon be about inspecting the new water habitats as possible places to lay their eggs.
Placing the pond in a shady area will help to reduce the build-up of algae, as will filling the pond with rain water rather than tap. Try to avoid getting earth into the pond as fertilisers can encourage algae growth. Another option is to create shade by dividing and planting plants you may already have in the garden.
Watching your pond establish and attract wildlife can be a joyful addition to a garden of any size.
There is more information on the RSPB website here with ideas for ponds.
https://www.rspb.org.uk/birds-and-wildlife/advice/gardening-for-wildlife/water-for-wildlife/making-a-pond/