... for example my circuit has power coming in at a jumper going through a diode, past a capacitor, to a regulator, etc but the ratlines don't really reflect the flow. Is there a way of changing the ratlines as you lay out?
Shift the components to where you want them on the board (& lock them there if you want them there forever), then run
VERIFICATION
COMPARE TO SCHEMATIC
The rats nesting lines will be recalculated based on which is now the shortest length to connect the components. If you placed the above components quite close to each other, the "new" rats nesting lines will show them directly connected together.
Initially I have no ground plane so I get a lot of ratlines which will ultimately end up as being grounded to the plane. How do you approach this? Do you layout the ground plane first or layout some connections and combine them later.
I lay down the ground plane first, then make some non ground connections. Every now and then, I regenerate the ground plane which will then be disconnected from your new (non ground) routes. Alternatively, just lay down your ground plane first, then set it to "unpoured", connect all your non ground connections, then "repour" the ground plane.
Remember that the auto-place function gives you a good head start (just lock in place the components that must be in set locations first like LEDs & switches) & the auto-router in DipTrace ver 3.0.0.2 actually works quite well.
ADDED: In fact since the latest release, I now reach for DipTrace over Altium & Proteus everytime. The latest ver 3 release has come a long way over ver 2.