There is no real simple answer so prepare for a novel here:
Just messing with the suspension settings without having at least a basic understanding of what you’re doing can lead to a bike that handles like crap and doesn’t ride any better than when you started. It’s like tinkering with a carb without really knowing what you’re doing; you’ll fiddle with it for days, chasing your tail, and never really get anywhere. It’s a sure-fire recipe for anger and frustration.
There are some things you have to have a basic understanding of before you go messing with things: spring rate, spring preload, compression dampening, and rebound dampening. I’m going to assume your bike has fully adjustable suspension (preload, compression, rebound).
-SPRING RATE: spring rate is set by the springs themselves so this is the one thing that isn’t adjustable without changing parts. Most bikes I’ve dealt with are OK as far as spring rate from the factory, assuming you’re not after all out corner burning performance; then they tend to be set up a touch too soft for us thick Americans.
It sounds like you after comfort so as long as you’re in between about 150-250lb your spring rate is probably close enough to work with. If you’re exceptionally light or heavy different springs may be in order.
-PRELOAD: preload is a certain amount of tension put on the springs at their “at rest” position. You want the suspension to “squish” a certain amount from fully extended when it’s supporting the weight of the bike and rider at rest. This is called “sag” and is pretty important to set correctly. Too little sag (too much preload) in front will result in “slow” steering response and a harsh ride, too much sag (too little preload) may cause instability in a corner and suspension bottoming (not good).
In the rear, too little sag will result in quick steering but a harsh ride and possible instability issues. Too much sag in the rear will result in slow steering response and possible bottoming and poor handling.
It’s adjusted with the pre-load adjusters (the big adjuster on the top of most forks and a thin “nut” on the shock body in the rear). You want roughly 32-38mm (1 1/4-1 1/2”) of sag in the front and 28-32mm(1 1/8-1 ¼”) in the rear. Since you’re after comfort, I’d aim for the high end on both of those unless you frequently carry a passenger or lots of weight, then go for the smaller number in the rear. If you have problems with the suspension bottoming, bump up the preload.
-COMPRESSION DAMPENING: the compression dampening controls how quickly, or easily, the suspension will “squish down”. Too little will allow the suspension to compress too quickly and can cause it to bottom too easily. It will also result in a bike that will “nose dive” when the brakes are applied or nose up on takeoff. This excessive “rocking” when on the brakes or on power will result in poor handling in a curve. Too much will not allow it to compress fast enough and will result in a rough ride and a bike that is “unsettled” when you hit bumps in a turn.
-REBOUND DAMPENING: Rebound controls how quickly the suspension is allowed to extend. Too little rebound will allow the suspension to extend too quickly and will result in a mushy uncontrolled ride. It can also cause “wallowy” handling. Too much won’t allow the suspension to extend fast enough and the bike will “pogo” over bumps. That means the suspension will not extend fast enough and the tire will actually leave the ground slightly as it skips off the back of one bump and hits the next. It’s kind of a “chattery” sort of feeling and it DEFINITELY makes the ride rough and unpleasant. It also greatly reduces your control as the tire will not be able to properly “grab” the pavement as it’s skipping along.
This is a VERY basic explanation so if you really
want to get into it I suggest some research on the subject.
As far as getting a softer ride; my suggestion it to back off the preload a little and take a few clicks of rebound out (softer). Compression is the last thing I mess with for a softer ride. Look to your owner’s manual if you’re unsure as to where each adjustment is made. Be careful though as going too far can cause some crummy handling characteristics.