Yes, this one is a very tricky balance. So, how do we have humility and confidence at the same time? When we have confidence-inspiring objects such as taking Joy with our good Kamma, generosity, etc., taking Joy when we see beneficial qualities arising, I think it's very helpful to learn how to reflect on how these things came to be. This helps to develop a certain amount of humility at the same time, understanding that any benefits we see from this practice depended on others. This helps us so we don't claim it for ourselves or just use it as a way to inflate our ego. Often what we encourage people to do is whenever they feel a certain amount of confidence, is to pass it on to the Buddha and allow the confidence in the Buddha and the Dhamma to grow. In this way we are developing a greater sense of Saddha in the Dhamma, and at the same time we're trying to lessen the tendency to claim all the development just for this ego.
This helps to keep this balance in a safe place, because it's very easy when we start to have confidence arise, to start to inflate our ego or start to get attached to the eight worldly dhammas in some way. By reflecting on the dependent arising nature of our understanding and using it to increase our confidence in the Buddha-Dhamma, aids us in lessening any conceit that may arise due to this. Confidence is a necessary quality to keep going in the practice. Without confidence we just don't have the energy. We are too overcome by doubt. So, a healthy confidence in ourselves and a confidence in the Buddha-Dhamma is very important.