What do former volunteers say?
On your project, sometimes ask the question: How would you normally solve this if there are no volunteers?
Make contact! This probably creates many fun and unforgettable moments. You also get to know the culture the best. Make real contact with the local population on your project. Look at their wishes and do not enter too much. Remember: you only go faster, you move forward together. So working together is really important if you want to make an impact.
Be open to what you will encounter during your volunteer work. Not everything will go as you expect or hope, but if you adopt a flexible attitude, unexpected things can sometimes turn out really well!