When placing platforms on vertical veins for Scouts to use, try to have it land between the bottom and middle of the vein. That way the Scout can reach higher and still be able to mine the bottom, speeding up the mining.
Don't waste your platforms, you don't have many. If you can dig instead of making a wonky staircase, do that. Unless you're extracting, then there's no need to hold on to the platforms.
When you're told a swarm is coming, place the turrets in an open area if possible as it gives everyone more space to maneuver. It can still be viable to use tunnels as chokepoints but your team would often have to be more experienced. Remember that dead Praetorians release a cloud of damaging gas, wouldn't want a tunnel filled with it.