Is there a difference between signing 'make' and 'making'?
In ASL, the same sign is generally used for both 'make' and 'making'. To emphasize the continuous, ongoing action of 'making' something, you might repeat the twisting motion slightly more than usual.
Does it matter which hand is on top?
Usually, your dominant hand rests on top of your non-dominant hand. However, it is perfectly acceptable if your non-dominant hand is on top. Just do whatever feels most natural and comfortable for you.
Can I use this sign for 'making money'?
While you will be understood, ASL often uses a more specific sign for 'earning' or 'making money' (sliding the dominant hand across the non-dominant palm). For creating physical objects or general tasks, this sign is perfect!