What to listen for when setting VTF?

The responses above reflect VTA (angle) changes but Gbb is asking about VTF (force) changes.

Sorry, as usual I can't read and/or comprehend. Below is a great link with info:

http://www.soundfountain.com/amb/ttadjust.html#DOWN

VTF and VTA are interrelated variables. As you change one, it affects the other. Once dialed in, minor changes in VTA won't require readjusting VTF (thank goodness for those of us who change VTA for every LP). But changes in VTF always require a re-listen for correct VTA.

To the OP's specific question on VTF, I highly recommend reading the "what to listen for" process posted by Lloyd Walker on his web site: Fine Tuning Your Turntable. I've been using this process for years with great results.
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I don't understand how people can change VTA for different Lps. Wouldn't that change overhang?

My experience with the UNIverse cartridge is that a lighter VTF works best. I used a method similar to one that Dougdeacon reviewed in an earlier string. It basically is to reduce VTF until mistracking occurs then increase it slightly. for the UNIverse, it resulted in a tremendous sound stage (resolution between the tracks or instruments/vocals) and clean/crisp notes versus some smearing of the musical notes. I found that increasing vtf did smear the sound and collapse the sound stage. As stated by rushton, VTF does require changes to VTA so my intial method (when i install a cartridge) is the get the vtf close, then optimize the VTA, go back and retune the VTF and finally reoptimize the VTA. I do this once then adjust vta only for various record thickness or when my ears tells me something has changed. I have found that sometimes ambient conditions (colder/warmer in my listening room) can impact my vta settings. As for other cartridges, (my experience with the airy3 or frog) was not nearly as dramatic as the UNIverse. The frog liked a slightly heavy VTF whereas the Airy3 had a wide spot concerning vtf. The Airy3 is very sensitive to VTA but fortunately has a pretty large sweet spot. In all cases, the ear is what i use to tell me when i am there. It also takes many attempts over several days to get it right as I have several times said "its perfect" only to come back a day later at tweak and find a better setting. My experience is heavy on VTF tends to augment bass and mids and dull the highs whereas too light on vtf results in a loss of bass, smears the mids and makes the highs shrill or tinny. THe other comment about overhang is true particularly when you move vta a lot. For very small changes in VTA, i would not even check overhang. As always, my experience may not be the same as others