as always, it is a bit hard to give any specific tips without knowing, what you are aiming for.
one of the most straight forward end effective techniques is probably patching square into air.
play around with the positive and negative attenuation (which suppresses/amplifies different harmonic content, where negative typically leads to somewhat darker results) in conjunction with adjusting air itself.
other interesting self patching results are reached by multing formant and feeding it back into fm input, with an envelope or lfo patched into fm index.
square into barrel is also nice to get rich harmonies, especially with formant somewhat ccw to dive into the frequency dividing utone territory.
edit: and obviously a combination of those. just quickly patched up something, mangrove as only voice and audiorate oscillation source. modulating air with square-out, fm with formant-out and envelopes/lfos on barrel, formant and fm index. and yes, couldn’t resist to add a bit of delay and reverb …