The alphabetical order is quick and simple. However, it can leads to harder reading when the number of attributes is important. For example, FontSize and TextAlignment have a close relationship, but can be few attributes (lines) away.

Here are the different groups, and their ordering, proposed.

• x:Key and x:Name
• Attached properties
• Positionning (HorizontalAlignment, VerticalAlignment, margins, z-order, stretch Canvas., Grid.)
• Box model (width, height)
• Typography (Font*, Foreground if text item, Text, Content)
• Visual (background, fill, foreground , borderbrush, borderthickness, Stroke, StrokeThickness opacity, visibility, style)
• Misc
• Event handlers

Pros:

• Code is ordered in a meaningful way,
• Related attributes are grouped.

Cons:

• Difficult to maintain without tolling support

Questions:

• How to handle custom controls attributes ? If you are using a vendor control suite (like Telerik or Infragistics), you may have a ton of "misc" attributes.

Your feedback is welcome.