Adding to Robert's reply there are a couple of other important aspects to RFQs (Request For Quote).
- Make sure that you answer every element of the original brief. Give examples where appropriate.
- Where possible provide choices for the client. This shows flexibility and leaves them in control.
- Always breakdown your costs. Some clients may buy extra services if the see you are competitive in a specific area or service.
If you are sending a hard copy then it should be on 100g quality paper printed at highest quality you can get and then bound properly. Put yourself in the client's shoes - the mail arrives and you have two quotes, one on 80g cheap copier paper with a staple at top left corner, the other on crisp white 100g paper wire bound with card back cover and clear front cover.
Remember - You only get one chance to make a first impression :)