The best time to wash your windows, glass doors and skylights is when the sun is not shining directly on the glass. If the sun is shining directly on the glass, streaks are more likely to form due to the cleaning solution drying faster than you can wipe it off.
Before you wash window glass, vacuum the frame, sill, or track. It is best to wash the frame, sill or track every few months with a sponge using all-purpose cleaner.
Use a commercial glass cleaner or a solution of 2 tablespoons of clear ammonia per 1 quart of water when cleaning glass. Wipe one pane of glass at a time and wash from side to side on one side. Then, on the other side, wash from top to bottom, this way if there are streaks, you can tell which side to rub again.
To clean those tough to reach places of the windows, the corners, use a cotton swab dipped in the cleaning solution. Dry with a squeegee, chamois, paper towel, or crumpled newspaper.
Note, kitchen windows and skylights may require a stronger cleaner if there is a heavy accumulation of grease and dirt.