The issue of raising money to support operating costs and staffing has always been challenging for NGOs. If you are applying for funding to a grant-maker, it is important to not under-estimate the hidden costs which should also be included in the budget. For example, rent, rates, IT, utilities, support staff etc. For staff whose salary is to be supported by the grant, then it would be expected that you consider a level of effort for certain roles and budget for these.
This might include a Finance Assistant and Finance Manager where you might consider the level of effort to be (for example) 10% for the Finance Assistant and 20% for the Finance Manager. This way you are taking some of the grants to pay for some operating costs. However, this does not give you a long-term way to raise unrestricted income to support your overheads.
Other more sustainable ways to raise unrestricted income is by getting regular supporters to give you money to continue your work. This requires a strategic approach and a long term plan which will include making people aware of the work you are doing. This can happen through talks in church or at community meetings for example showing people how you are making a difference. After doing public talks, you can ask for donations and/or ask people to commit to giving a small amount of money each month to help your cause.
However, if you do manage to recruit regular supporters, you will need to keep them engaged through regular communication about your work and progress. It might also be possible to work with schools as part of a youth citizenship approach. If you can build linkages with School Heads who are community-minded, you might be able to see if the school will raise funds through school events run by the children.
You can also hold community events which attract people and then collect names and contact details to try and follow up afterwards. Some NGOs are able to recruit groups of people to fundraise for them as volunteers and while it may take time to establish a network of regular supporters, this will provide you with unrestricted income that can be spent on your operating costs.