I usually use the lash strip as a 'holding bay' whilst I make my fan but you can substitute that for some double sided foam tape, Bostik Glue dots or Scotch restickable dots. These are a good replacement if your lash strip just doesn't retain the right amount of tack. The adhesive surface will act as an anchor allowing you to manipulate the lashes into place whilst keeping the bases together.
How to make the fan
Isolate the number of lashes you would like.
Pull those lashes towards and press just the base of the lashes onto the edge of the holding bay.
Allow the lashes to splay and then manipulate so they are spread evenly
Grasp tightly and remove.
Remove some tack from your holding bay before you begin. If it is too tacky then you will have trouble manipulating and removing your fan. If your holding back is not tacky enough then when you place it will fall apart.
Bostik glue dots are much smaller than Scotch restickable dots so save on space.