Flower rich meadows developed over hundreds of years. Cattle were removed from summer leys in spring and the grasses and flowers allowed to grow. This was cut for hay at the beginning of July, or later, in September. After a month or so the cattle were returned for winter grazing. Replicating this pattern of management enables you to create a wildflower meadow. No you don't have to get a herd of cows!
First you need to choose a suitable location, preferably an open sunny site, maybe linking with other types of habitat. A site with poor infertile soil and/or subsoil will provide the ideal setting and unless you specifically want a wet meadow it should also be reasonably well drained.
The simplest way to begin is to introduce some bulbs or plant plugs into an existing lawn. Arrange the plants of each species in clusters to achieve a natural looking effect, 4 or 5 plants per square metre. Scrape away an area of grass to reduce competition, remove a small divot, set the plant, heel in firmly and finally water.
The problem with trying to convert an existing lawn is that the turf probably includes rye grass, a vigorous and hard wearing grass and of course it will have been fed and pampered. Given their freedom the vigorous grasses take over. You are then faced with the choice of either reducing the soil's fertility (continue mowing, removing the cuttings and not feeding for several years) or of creating a meadow from scratch.
This is where the hard work comes in!