All the cake decorating books show how to ice a cake using a thin board, then put onto a covered thick board, which its displayed on.

It would defenitily come out neater, but how can i put my one tier on one big cake board without making a mess when crumb coating and icing ontop of my covered board??

Rather than worry about messing up your display board why not use 2 boards? They are really cheap. I cut mine to the size of my cake (if the cake is an odd shape) then put in on the display board

i think i will try that for my next one, but i wondered if everybody does this?

i suppose its more exp when making small quantities and less often. when i start bulk buying ill feel happier about splurging on making my life easier ;)

Try using four pieces of wax paper underneath yr cake and covering yr board . once u have finished crumb coating, icing, etc  pull the four pieces out and do yr border. when u place the wax paper, place it closer to the edge, but still underneath the cake

It can be done easily for economy in this case or in a pinch if you need to.

Center the cake on your finished board.  Tuck strips of parchment or waked paper under the edges of the cake, to protect the board.  Decorate your cake.  Pull out strips.  Clean cake board.

A decorative edge can be then piped to cover the bottom edge if you want.
 

I decorate the cake on the smaller board, the same size as the cake, then transfer the whole thing to the covered display board.

I do the same as Dayti, but lately with all the pretty new papers I've been using, I have to place clear paper on top of that.  The clear paper makes it easy to clean up without marking my covered boards.  So I can eliminate that second board.