Abu Dharr reported: I said: Messenger of Allaah, which of the deeds is the best? He (the Prophet) replied: Belief in Allaah and Jihad in His cause. I again asked: Who is the slave whose emancipation is the best? He (the Prophet) replied: One who is valuable for his master and whose price is high. I said: If I can't afford to do it? He (the Prophet) replied: Help an artisan or make anything for the unskilled (labourer). I (Abu Dharr) said: Messenger of Allaah, you see that I am helpless in doing some of these deeds. He (the Prophet) replied: Desist from doing mischief to the people. That is the charity of your person on your behalf. (Muslim)

Lessons to Learn from this Hadith:

1. A person who cannot do one of the good deeds, can do some other good deed in order to catch up for extra rewards.
2. An artisan can help people, that is a kind of charity. But if you are not an artisan, then try to help that artisan in any way possible, that will be considered as charity.
3. If that is also not possible, then do not harm people, that is also considered as charity.