Tiles have been the popular way to do it for the last several years. Most economical if you are attaching them straight to ceiling. Much more if you have to create a drop ceiling (due to attic space) and lose some height in the room.

The old way of drilling small holes all over the ceiling from the attic and fixing fiber strands with (epoxy, silicon, etc.) back to a controller. Was extremely time consuming = very expensive.
Unless it was for your own place or a friend you were working for free. Then the fiber & light controller are the cheapest way, material wise. Whole kits start at less then $200 for 200 3 sized fiber, with twinkle effect LED light engine [covering about 50 sq.ft. or less].
But if you don't have crawl space above the ceiling, you would still have to build a drop ceiling to do it. Loosing some height in the room and the cost of the new drop ceiling.