Uganda has more volunteering opportunities than many African countries, thanks to a number of good grassroots organisations. The Uganda Community Tourism Association and Pearls of Uganda are in touch with many communities around the country and can connect you to a variety of projects, including tree-planting and teaching. Many volunteering roles involve an expenditure/donation on top of living costs.
If you’ve ever thought about living and working in Uganda, then why not teach English as a foreign language (TEFL)? It could be the key to funding your travels and experiencing new cultures in a totally new way. You don’t need teaching experience or even the ability to speak the local language – although you might learn it while you’re out there.