I have an area of rough grassland surrounded by briars that I'd like to cover in various wild flowers, and seeds or advice would be most welcome
Hi barry. If you want to keep the rough grass as is then I suggest planting plug plants as seeds will struggle to compete with the existing grass. If you want to do the seed thing then you'll need to dig out the grass and prepare the soil as you would for planting any seeds. There are a few good websites where you can buy native wild flowers as either plugs or seeds and wildflower mixes. Don't forget bulbs but do be mindful of flowering times and when you'll be cutting back. The wildflower websites give plenty of information.