I have noticed lately that many sellers have negative feedback from buyers complaining about bad quality vinyl or item being difficult to apply.

Applying vinyl is no easy task and very easy to mess up.  Reason why many professional vinyl installation shops exist.  There are specific steps taken by these shops to make a professional look to the decals.  Not something you can just get off instructions.  Even with instructions, you need practice to make the decals work and look great.  Sometimes you get lucky and everything turns out very good.

I used to work in a shop where we designed, print and cut vinyl and applied the decal. I have experienced the tips and tricks of how to apply the decal.  Much of the reason I buy many vinyl items.

One particular item I see with many complaints are vinyl decals made for taillights.  These users complain about being poor quality.  Specifics like the decal rips, wrinkles or just generally difficult to install.  The reason for this is not poor quality, however, due to the smallness of the item and the intricate cuts, these decals need to be handled with much care.  You cannot (repeat CANNOT!) just slap these on.  As with all applications, you must be patient!  I cannot stress that enough.  If you want quality, have the the patience to apply the decal.  If your not patient you will not have a good application.  Which is at no fault of the seller.  Whether instructions were provided or not.

Generally, you want to apply the decal with temperatures of at least above 40 degrees.  And the humidity should not be more than 50% and should even be significantly less.

Certain sizes require different techniques, but all should start from the bottom center and work out and up.  This reduces your chances of having bubbles.  Even the most professional decal applicator will have bubbles at some point, so don't worry if you do get one.

To fix this, make a small hole at one end for small bubbles or a small slit for large bubbles and with your finger, smooth out the bubble.

If you were new to applying decals.  I urge you into searching online for tips on applying decals.  Most tips are general in application and work for any type of application.