I also have a plakat dragonscale. He's a shy boy, but he is nortorious for trying to burrow under things. I keep their decorations simple - plants and a large, open hiding place where they feel safe, but won't be trapped. I also use large rocks, like the glass kind you see in small tanks. They're just as pretty in larger ones and are a breeze to clean.
A wire strainer to rinse them off in during monthly full water changes is a great buy, too. I got a decent sized one for $1.50 and it helps clean them twice as fast, and twice as good. It'll help keep your betta healthier if you can keep his home cleaner.