Key technical aspect is amplification, as OT expect line level in its inputs.
You might want to go lofi and use e.g. compressor gain as well as other volume levels to amplify a low level signal such as a microphone, a guitar or a piezo.
But it’s better IMO to use a dedicated amplifier.
I use H4n, SP404, Mutable Instruments Ears or simply my mix table amps for such duty.
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About OT use : choice is yours between pickup machines (if you need overdub and don’t have precise external tempo to enforce) and Flex with recording buffer (pretty cool to play with slices, works great for continuous sampling and slice mayhem, way for more experimental results)