1
Put your hood up, it's raining.
To express this, you can sign 'rain' with a matching facial expression, and then use the sign for 'hood'. The visual nature of the sign makes it clear you are suggesting they use their hood for protection.
2
I love wearing this hood.
Point to yourself, sign 'love', and then sign 'hood' while indicating the clothing you are wearing. You can add a comfortable, happy facial expression to show how much you enjoy the garment.
3
Where is the hood on this jacket?
First establish the topic by signing 'jacket', then sign 'hood', and finish with the 'where' sign. Remember to furrow your eyebrows at the end, which is the grammatical marker for a 'wh-' question in ASL.