Sometimes creating an entire estimate for a one bid item project can be complete overkill. This suggestion comes from many years (back in the DOS days) that still is valid today. Consider for small estimates (one bid item) creating an estimate that will contain a years worth of projects. The bid item will be the actual estimate and of course you can break it down into many activities. The current biditem, which in this case is the estimate, would be additive. The previous bid items (you have already bid these estimates) would be non-additive. Just like any regular estimate you can have indirects that will be spread to the additive biditem. Markup and price the biditem and your estimate is done. The advantage of this approach (one biditem – one estimate) is that you won’t be creating a multitude of estimates for small projects and in one estimate you can quickly copy down any previous estimate for quick revision and speedy quotes. 
Try it out and see if this approach simplifies your bidding of small projects.
As always, let me know if you have any questions.