How to hold the curtains bar in a cheap, easy and clean way. only one small whole!. Curtain bar must arrive side to side walls (if not use 2 or 3 hook hangers from the ceiling instead)
Step 1: Pieces You Need. Meter, Drill and Screw
step one: meter the distances to window and ceiling in both sides. Drill a whole (in this case 5 driller is enough) and introduce the plastic wall plug (n5).
Then search in you tool box for 2 pieces of plastic or metal around 1cm long (you can use screw nuts for example or cut 2 pieces of plastic from an old pen). This two pieces must have a small whole in the midle and be as more wide as posible to adjust into the whole of the curtain bar. It is just to prevent unwanted movement and noise when moving the curtain. If you dont care about you can even use the screw directly to the wall without the plastic piece, just leaving the screw 1cm out of the wall.
Step 2: Adjust the Curtain Bar
If flexible, cut the bar the same size as the distance between the 2 walls. If bar is too rigid, the cut it 1cm less than the distance between walls. Be carefull in this process as if you cut it too short it will be useless. It is better cut too long and then cut small pieces until it comes in..
When you have both sides screwed with the 1cm plastic pieces to the walls (and an extra hook from the ceiling at midle distance from the walls when the bar is longer than 150 cm or curtains are too heavy), measure and cut the bar (try if it comes in), then introduce the curtains, hold the bar and curtains.
A last step is required...
If too stiff the bar and you had to cut this lesser 1cm, then when you introduce the bar in both sides, you need to put around the plastic pieces a rubber ring 0.5cm thick (less is also usefull but curtain bar will move a litle because the gap). If you do not so, curtain bar will easily fall down..
Dont permanent fix the rubber rings to allow bar removal to wash the curtains once in a while (they get very air polution dirty and is healthy to wash them as often as the polution of your city is, in my city I have to wash them once bimonthly).