When first contacting a host remember that the host has little idea of what you are like, your email is their first impression of you.
The importance of your first message to a host cannot be underestimated, the way you write this will have a large bearing on whether a host feels that you will be a suitable helper and guest at their place.
Write a good message and there is a much higher chance of getting a positive reply. If you write an inadequate email that is rushed or shows no enthusiasm it’s far more likely to get a "no thanks" in reply or no response at all.
Generally, hosts like people that are self reliant, able to be independent, make good decisions, polite, honest and helpful.
It’s important then to consider how to relay this in your first contact message.
How can this be done?
By including these, you will have a better chance of endearing yourself to the host. This is likely to make them feel that you have taken the time to carefully choose them and that you are sincere about going there.
It’s usually important to keep your message concise, don’t include loads of information about yourself. That’s what your profile is for - make sure it’s well filled out because hosts will go there to find out more about you. It’s a sign of a serious helper if you have good up-to-date information in your profile - remember pictures say a great deal and if you take the time to create a video about yourself, this shows that you are enthusiastic and committed. If a picture is worth a thousand words, how many is a video worth? ;)
Remember to stay in regular contact once you have established a connection and agreed to go and help a host. This is especially important if you have arranged this far in advance of the time you plan to visit. Plans do change, but keeping hosts informed is much better than cancelling at the last minute.