Use Different Tones of Foundation
To make a crooked nose look straight use two different tone foundations, each for one side. In this way your crooked nose will give the delusion of a straight nose. To achieve this result one shade of the foundation should be dark in colour than your skin colour and other should be a little lighter. Use the darker foundation on the area where your nose has a prominent bend. It forms shadow area. You can find this prominent bend area with your index finger by pointing it vertically towards the corner of eye and then even it with the bend. Now apply dark tone foundation in that area and then blend it in the skin.
Use the same method to apply the lighter tone foundation on the other side of your nose. Then blend both tones of foundations in a way that it will give a natural look.
Use Cream Highlighter
Usage of cream highlighter is another option to make a crooked nose look straight. To achieve a good result use a complimentary shade of cream highlighter, as they are available in almost all tones. This highlighter cream will be applied to bridge of the nose. After blending the highlighter will give the delusion of a straight nose.
Select the Right Lip Color
Through different makeup techniques you can also make your crooked nose look straight. For instance use a light shade of lip gloss rather than a bold one. It will draw the attention from nose to centre of your face. Aside from this use black eye liner and dark eye shadows to create smoky eyes, as this will also bring the attention towards upper part of the face.