Interesting things I read:

• make sure your angles are accurate. If you draw a cube, your drawing should have a 90º angle for a cube.
• if your lines need to be parallel, make sure they are parallel or else it will look off
• Whenever you have to draw a circle, do so by inscribing a square
• an important part of perspective is dividing your plane evenly. For triangular planes, you can do a cross where you draw the line at the same angle and then draw a horizontal line and it will look parallel in perspective
• Measuring lines are good to divide your defined plane. Draw a horizontal line and divide it equally, then draw vanishing lines to them
• larger objects in rooms need the most detail to perspective. Smaller items do not need it
• treat rooms like a box