The structure provided by vegetation is sometimes more important than the types of plants used. To provide the best amphibian and reptile habitat it’s vital to create a ‘mosaic’ of plant heights.
Densely planted, low-growing vegetation provides shelter, while more open areas provide basking opportunities. Remember to mix it up so all the different habitats are accessible from one another.
You don’t necessarily need to plant anything specific (though plants that attract insects are good), simply allowing patches of lawn to grow long will be beneficial.
Control of trees and scrubby vegetation may be needed to stop the garden becoming too shaded but remember shrubs and hedges are also important habitats. All sorts of wildlife will be attracted by the different ‘microhabitats’ created.