with enclosures, they obviously need a large space, and best to have a house with indoor dens (each with a platform and waterbowl) for them to go into aswell (the number of dens should be at least one more than the number of cats you are holding in the enclosure so that you can move them about easily)...outside should be a mixture of substrates, like grass, wood bark etc...and they should have something high up that they can look over the surrounding area from like a platform. lots of different plants and fallen tree logs are a favourite too.
you can do all different things for enrichment.... hiding meat in log piles is one of our lions' favourites, also hanging it up in hard to reach places, or just generally hiding it around the enclosure - the more furniture you have in the enclosure, the more things you can do with the meat...another favourite feeding technique is cutting the meat into small chunks and either hiding them in all different places in the enclosure or throwing them over the fence so that the lions have to watch them and run after them etc.