There were some interesting discussions about this on a space elevator forum. Counter weights aren't practical because they reduce by half the amount of weight that can be carried. Another problem is the car damaging the cable as it crawls upward.

Interestingly while I was there an engineer suggested an idea for deploying the cable which is now one of the main ideas. The cable would be tapered so it is wider at the top since that part has to carry more weight.

First apparently they would deploy a thin cable maybe no thicker than sewing thread. Then they connect it to a cable that gradually increases in size so over time as they spool it up from the ground to orbit the cable gets thicker and thicker. Then at some point the cable being fed upwards is tapered off again so the cable lowest to the ground is the thinnest.

This apparently is easier than taking a large ribbon into orbit. If you don't taper the ribbon so it is narrowest at the bottom then even with an ideal CNT strength it can hardly carry anything since the cable itself weighs so much over tens of thousands of miles.

The bottom needs to be moored to a platform that can be moved because the ribbon might have to be moved to avoid satellites and space debris.