Yes. Find a point where it burns, hold for at least a count of 5. Do the same on the other limb/joint/side of body and return to the one you start with to deepen the stretch. This will give you the most out of each session
I like to hold one pose for 30 seconds. But obviously some poses are harder than others. Take your time, give yourself 15 second breaks in between, do 2 sets of these poses 15 minutes each.
You should hold poses for at least a slow 10-count but longer is better. If you are very still start with 10 and relax then repeat. Gradually build to a longer count.