What is the best procedure to achieve super skinny arms? (Photos)

Generally liposuction  / liposculpture is the best treatment, provided that : 
there should be a sufficient amount of fat in order to make a difference. 
In your case , at first glance, there seems to be only a small to moderate amount of fat , hence only a discrete improvement can be made.
In some patients, skin removal  + liposuction will be the answer, which is called ' arm lift ' .
In  patients with loose skin or moderate amounts of fat , non-surgical options are also available, although surgery usually is the most efficient solution

In order to substantially reduce the size of your arms, you have to have fat to remove. Additional decrease in size comes from tightening of the tissue utilizing energy such as laser and Jplasma/Renuvion.  Another consideration would be muscle shrinkage using botox. 

From your photos, you appear to be a good candidate for BodyTite.  BodyTite does not remove any fat, but it is capable of producing a 45% contraction in tissues.  It can be combined with liposuction to improve contours dramatically.  Results can be seen immediately after one treatment and are more evident over three to six months post-treatment. Wait until six months to fully evaluate the aesthetic results.  Sedentary activities can be resumed in two to three days and full activity with exercise within two to three weeks.