Tom, If you already tune your guitar to a more resonant pitch, you might want to try what I think the best method, aesthetically and scientifically, which is to tune to the resonant pitch of the lute cavity--every open-ended cavity has a fundamental resonance, and the overtones which will pick up what the strings are vibrating to.
Slack the strings so much that you can hold them aside a bit from the rose (they won't resonate at all, now) and sing as low as you can into the rose, gliding slowly up. At certain points you'll hear the body of the lute singing back strongly, and feel it in your fingers holding the neck. Note the pitch from your tuner and keep going--it will probably give strong resonance at two points, the fundamental and the fifth. If the fundamental is too far off to practicably string it for, then use the fifth. Retune, restringing if necessary, so the strings are in harmony with the cavity's resonance. The difference is amazing. If you're not the sort to be convinced, as I am, by the physics, the sound will decide it--as it should. The resonance of the instrument will be greatly magnified, as will the volume, and even the clarity of the plucked notes and their overtones. I have done it with two 64cm lutes, one responded at E and the other at F. They are much the richer for it--totally different instruments. They stand up very well to a voice they accompany, without being overwhelmed. The harmonic synergy between the voice and lute (if it's you singing) is palpable. Let us know whatever you try. -James di Properzio
