Despite concerted effort, we have yet to stitch together a complete and uninterrupted cosmic timeline. 21cm cosmology promises to directly probe cosmic dawn and the epoch of reionization, but in practice it is riddled with challenges: bright foregrounds, instrument systematics, and model degeneracies are chief among them. Luckily, combining 21cm with other probes allows us to overcome each of these hurdles. In this talk, I will first show how cross-correlations with other line intensity maps will likely yield detections with current instruments, including a dedicated effort now underway with COMAP-Wide and LOFAR. Following this, I will present a data-driven foreground mitigation technique that uses intra-dataset cross-correlations to rid line intensity maps of their contaminants. Finally, building on recent work from UIUC, I will show how cross-correlating radio and millimeter-wave CMB maps allows us to distinguish between cold gas and excess radio background models at cosmic dawn.