Custom pieces of Lego that would add interest to the basic stock.
Love this idea!
Ann Marie Shillito commented
'Lego compatible' blocks can be downloaded from Thingieverse and added to to customise. We did this, using our Company's, Anarkik3D's 3D haptic sketch modelling software (Cloud9), and A1 Technology 3D printed a test piece using a Rapman. Beyond what you are asking for (customise and add to basic stock) we also did this to demonstrate that by using our 'very easy to learn and use' system, artistic and creative people will be attracted to Lego as they bring their own ideas to personalise their creations. This would also extend the Lego user base further to include so many others. Lego is such a great product and amazing things are being built with it.