Of course, there are lots of things you can "decorate" a tank with, but my opinion is that plants and bogwood, maybe some rocks, are all that is necessary. There are those who like to have wrecked cars, sunken galleons or whatever but personally I find those extremely "tacky". There's no accounting for tastes, though.
You will probably find difficulty in growing plants with a pure sand substrate. They are much more likely to succeed if you have a proper plant substrate under the sand, either one of the expensive special media you can buy, a cheaper alternative of pond compost or (like me) the free soil from your garden. Whatever, plants have a much better chance than in pure sand.
