Always take a picture of the drive side. The only time a picture of the non-drive side should be posted is when you are selling the bike or to illustrate a problem.

Tires should be installed so that the valve stem aligns with the tire logo.

Valve stems should match - same brand tube, same length stem.

Wheels should be rotated so that valve stems are at the 6 o'clock position or at least the stems should be at the same position for both wheels.

Crank arms should never be horizontal or vertical. Pedals should not be at 3, 6, 9 or 12 o'clock position. The drive side pedal is best placed at 4 or 5 o'clock whenever possible.

Don't have a busy background like chain link fences. Simple backgrounds are better. Less is more. Contextual backgrounds are nice - a mountain bike in the woods or a road bike on a nice country road, etc.

Clean your bike. Then clean it some more.

No valve caps, knurled valve stem nuts, reflectors or spoke protector disks. Well done vintage bikes may be exempt from this rule.

Get the fit dialed in before you post.