Make tiling easier! 2d game editor without tiling features is nonsense. You wouldn't copy-paste sprites or press Enter if you have a huge level that should consist of thousands tiled sprites.
Just add feature like this, similar to that "drag sprite and press enter" but it should works like brush. I mean, drag sprite, hold some key (shift, etc.) and move mouse over layout - and it will automaticaly fill grid cells with selected sprites.
P.S. Sorry if my English is bad