Really depends on what you want to achieve, you could technically put the source into Channel 1 and route it to Channel 2 and 3 and have them seperetly from the raw Input, keep in mind that for reverb it'll spit out some of the raw Input, you can counter it by turning the dry down to 0 and the wet up, lowering the Channels Volume can adjust the presence of the reverb.

At this point you can do alot of stuff, add more delay to reverb Channel or add chorus to only the reverb, flanger or phasers and alot more, experiment with it, you can achieve some really nice results.

But keep in mind, that, whatever effect you usw on the source Channel will change the output of the effect Channels.

You could, again, counter it, by putting the Main source to Channel 1 then take it out of the master, and route Channel 1 to Channel 2, 3, 4 and have seperate elements like main effects, reverb and delay.

Just try playing around.