I usually set up my non-animation (one final pose only) dynamic runs with 60 frames and do the following steps.  It still doesn't always work--sometimes you have to play with the stretch, drape, and thickness numbers. 

1. Click below the timeline and change that number to 60

2. Load your figure in frame 1 with nothing morphed.  Turn off all the IK and, in most cases, zero the figure (I'm not at my Poser PC so I can't remember the tab you use to do this.  If you need help, ask and I'll explain later.) Most dynamic clothing is set up for the zero pose.  Press the + at the end of the timeline to create a frame.

3. Skip to frame 10 and press the + again.  This gives you 10 drape frames with no morph changes.

4. Skip to frame 30 and morph your figure but don't change the pose.  Press the + again.

5. Skip to frame 45 and add your pose. Deselect the loop dot at the left edge of the timeline.

6. Run your simulation with 60 total frames, 10 drape frames, and colliding against every body part that the item will touch. 

I add the extra 15 frames to the end so that the clothing can settle so it looks like the person has been in that pose for a few seconds.  Sometimes frame 60 looks better, sometimes frame 45 looks better, sometimes it's a frame in between.

Another hint from someone who was struggling with an older PC.  I learned to not apply textures until after all the cloth and hair simulations have been run.  The textures seem to slow it down and cause it to crash more often.

Another tip if your morphed figure is significantly thinner through the waist than the unmorphed figure in frame 1.  Set up the simulation but don't run it yet.  Go to frame 1 and change the x and z scales on the FIGURE (not the cloth) to 90%.  Do the same at frame 10.  Check frame 30 to make sure that the x and z scales are back at 100%.  You will have to set the stretch lower than a normal simulation or the cloth can break.  This gets you nice, tight fitting dynamic clothing.