Fill your vase with cold water (cold water keeps your roses closed longer. However if you want them open like mine in the photo, use warm water). Tape off your vase with crisscrosses, making sure there is an open center.
Snip off all the greens and thorns from roses. Cut then down to a size you like. Place the first rose in the center hole and work your way around by putting a rose in each hole. Do this until your roses (I used 24 for this arrangement) are used up.
Don't be afraid to re-position your roses by pulling some of them back out. Just do this careful so you do not pull up the tape. You can always add a bow (a vintage doily would be pretty with a pin of some sort) and greenery and fillers. Of course if you added greenery, this must be done before the flowers are put in, and in the same process of putting in the roses, filling in each hole.