Least amount or expensive coax.
Just look at a couple data sheets and check the attenuation for 1090 MHz.
If you’re really looking to min/max, there is a thread here: Building a new receiver, this is going in a prime location - Suggestions for receiver/preamp/filter please
It’s pretty long, there is a blog post on what components the thread starter ended up with: Rebuilding and raising my ADS-B receiver | QSO365
Don’t expect such big range though as the horizon from your location will dictate how fare you can receive. See this handy page to calculate what you can expect: GitHub - wiedehopf/tar1090: Provides an improved webinterface for use with ADS-B decoders readsb / dump1090-fa
1090 MHz is line of sight, everything but clouds will block your signal.
One tree will hamper reception but usually not destroy it.
A forest will attenuate too much to get far away signals with the line of sight going through it.