Keep it clean.

This custom offline map will allow you to create a crosshair that fits you better and can improve your aim and ability.

http://steamproxy.net/sharedfiles/filedetails/?id=308490450

To use the map, follow these instructions:

1. Subscribe to the map in the above link

2. Open CS:GO

3. Play>Offline With Bots

4. Select "Workshop" up at the top

5. Select the map

6. Press Play

7. Select "No Bots" and continue

8. Mess around with the settings until you get something you're happy with

The below video also gives a good rundown of the map, as well as what certain options do to help you in creating your crosshair:

https://www.youtube.com/watch?v=f1NFaVJZMZo