Why don't you have a garden party?  
Rain or shine its a lot of fun.  Friends and  neighbours will want to get involved.  A BBQ and a Bring & Buy stall are a good start. Home made ice cream was a big hit at one event. A small private raffle can raise money before the event and during the event.   Local businesses will donate prizes. They are often very generous.  Hotels and restaurants may donate a Dinner for two. A Travel agent might donate a weekend in Paris. These are prizes that have been donated in the past.  Ticket sales are often less than the value of prizes so you don't need a lot of prizes just a few good prizes. If the event is not open to the public there should be no need for a permit but best to make sure and ask.
Tell us about the event and we will send a letter to allow the use of our Registered Charity number.