The results are in! The best ratio of cement to sand for concrete crafts has been found. 5 recipes tested, here's the winning ratio mixture!
Concrete Garden Bench : 9 Steps (with Pictures) - Instructables
How To Make Concrete Vases
DIY Concrete Planters (2 Different Ways) - Step by Step Tutorial
Concrete Basics - Mixing and Casting Cement and Sand - Simple
DIY Drop Cloth & Cement Planters - Infarrantly Creative
Sakrete Mortar Mix 60-lb Mortar Mix in the Concrete, Cement
HOW TO MAKE - CONCRETE STEPPING STONES - full tutorial
The Best Ratio of Cement to Sand (for Concrete Crafts) - Artsy
Concrete Sphere Tutorial, GARDEN, DECOR