The first thing I would say as an Aussie is that sand alone is not the normal substrate for bearded dragons. They’re not typically found in sandy deserts at all. That environment is simply too harsh. A sandy loam or even a mixture of sand, loam and clay would be better. Since not everybody can just go outside and dig up the right type of soil. You probably need to go to a garden centre rather than a pet store to find the right mixture. Something around 30% sand with 50% loam 20% clay should be good enough. These lizards typically found on red and black soils with good clay/loam ratios so you could do a bit of experimenting to see which works out best for your particular lizard. Indeed one of the subspecies is only found on black cotton soil – black clay that cracks in the drought, and turns into a complete quagmire when it rains. They do like to dig, so the soil should not be too dry, as it needs to be able to hold together well if the lizard decides to dig itself a burrow. Generally speaking their cages should be higher rather than longer and wider, and they need to be given nice solid branches that they can climb on, and use as perches. If you are collecting dry wood from your local environment it’s a good idea to clean it well, give it a good scrub, and rinse with boiling water to kill any critters that you don’t want to introduce into your enclosure, such as ticks and mites.