Feeding is straightforward but worth getting right. Meaty cat or dog food, or a specialist hedgehog food, is a better choice than bread and milk, which can cause digestive upset. A shallow dish of fresh water left out overnight is just as useful as food, particularly during dry spells in summer.
Food choice should shift with the seasons. High-fat foods such as fat balls and suet blocks suit the colder months, when birds need extra energy to maintain body heat. During the breeding season, softer foods and mealworms are more useful, since adult birds feed these to chicks that cannot yet manage tougher foods. Sunflower hearts work well year round and avoid the mess of husks left by whole sunflower seeds.
Access is usually the first barrier. Solid fencing and walled boundaries cut a garden off from the wider network a hedgehog relies on. A gap roughly the size of a CD case cut at the base of a fence panel, sometimes called a hedgehog highway, lets them pass between neighbouring gardens without needing to cross open roads or driveways.
Native hedging is a strong starting point. Hawthorn and holly, insect houses for garden pollinators example, provide dense shelter and nesting sites through spring and summer, then carry berries into autumn and winter when other food is scarce. Nectar-rich perennials planted alongside give pollinators a working food source through the growing season rather than a single short burst.
Fish are worth thinking through carefully. Ornamental fish will happily eat frogspawn and tadpoles, so a pond intended mainly for amphibians is usually better left fish-free. Leaving some leaf litter to settle at the bottom over autumn also gives amphibians a place to shelter through the colder months.
Frogs and newts are useful garden residents, feeding on slugs and other insects, and their presence is generally a good sign that a pond is in reasonable health. Attracting them is mostly a matter of getting the habitat right rather than anything more involved.