Here is a goal: proper consistency of concrete for a mould

How would you accomplish this goal?

pick from the following.
- Start with a little bit of concrete powder and mix in water until your mix looks wet with clumps, like oatmeal.;
- Start with a bag of concrete powder and mix in oil until your mix looks wet with clumps, like oatmeal.;
Start with a little bit of concrete powder and mix in water until your mix looks wet with clumps, like oatmeal.