As TSG said two of the options are to incorporate the transition, or hide it. It is hard to know which will work best in your space without knowing how big the crown will be and what style you have in mind, etc. Here are some examples of incorporating the window trim with the crown: [[(https://www.houzz.com/photos/traditional-bathroom-traditional-bathroom-new-york-phvw-vp~1034813) [Traditional Bathroom[(https://www.houzz.com/photos/traditional-bathroom-ideas-phbr1-bp~t_712~s_2107) by Stamford Architects & Designers Sound Beach Partners LLC [[(https://www.houzz.com/photos/shingle-style-home-in-hanover-nh-victorian-bathroom-burlington-phvw-vp~106093) [Traditional Bathroom[(https://www.houzz.com/photos/traditional-bathroom-ideas-phbr1-bp~t_712~s_2107) by Norwich Architects & Designers Smith & Vansant Architects PC [[(https://www.houzz.com/photos/chestnut-street-bathroom-traditional-bathroom-boston-phvw-vp~96002) [Traditional Bathroom[(https://www.houzz.com/photos/traditional-bathroom-ideas-phbr1-bp~t_712~s_2107) by Boston Kitchen & Bath Designers Venegas and Company [[(https://www.houzz.com/photos/case-design-remodeling-inc-contemporary-bathroom-dc-metro-phvw-vp~87107) [Contemporary Bathroom[(https://www.houzz.com/photos/contemporary-bathroom-ideas-phbr1-bp~t_712~s_2103) by Bethesda Design-build Firms Case Design/Remodeling, Inc. [[(https://www.houzz.com/photos/weston-residence-traditional-bathroom-boston-phvw-vp~2583807) [Traditional Bathroom[(https://www.houzz.com/photos/traditional-bathroom-ideas-phbr1-bp~t_712~s_2107) by Boston Architects & Designers Catalano Architects [[(https://www.houzz.com/photos/louisville-traditional-bathroom-atlanta-phvw-vp~116461) [Traditional Bathroom[(https://www.houzz.com/photos/traditional-bathroom-ideas-phbr1-bp~t_712~s_2107) by Canton Furniture and Accessories The Furniture Guild Or transition with window treatments: [[(https://www.houzz.com/photos/fan-victorian-bathroom-los-angeles-phvw-vp~207997) [Traditional Bathroom[(https://www.houzz.com/photos/traditional-bathroom-ideas-phbr1-bp~t_712~s_2107) by Los Angeles Interior Designers & Decorators Just Joh [[(https://www.houzz.com/photos/bathrooms-traditional-bathroom-phvw-vp~2678396) [Traditional Bathroom[(https://www.houzz.com/photos/traditional-bathroom-ideas-phbr1-bp~t_712~s_2107) by Chester General Contractors ColeBuilt [[(https://www.houzz.com/photos/vacation-home-on-lake-michigan-traditional-bathroom-grand-rapids-phvw-vp~3286791) [Traditional Bathroom[(https://www.houzz.com/photos/traditional-bathroom-ideas-phbr1-bp~t_712~s_2107) by Detroit Interior Designers & Decorators Urso Designs [[(https://www.houzz.com/photos/eclectic-bathroom-eclectic-bathroom-atlanta-phvw-vp~137747) [Eclectic Bathroom[(https://www.houzz.com/photos/eclectic-bathroom-ideas-phbr1-bp~t_712~s_2104) and this one, sort of in between: [[(https://www.houzz.com/photos/bluff-plantation-traditional-bathroom-atlanta-phvw-vp~58127) [Traditional Bathroom[(https://www.houzz.com/photos/traditional-bathroom-ideas-phbr1-bp~t_712~s_2107) by Charleston Architects & Designers Frederick + Frederick Architects I hope this gives you some ideas!

Thanks for the replies so far. The window sill would be replaced if we go with the wider casing and may need to be replaced if we go with the narrow too. The padding out would put an inch piece of wood on all sides of the insides of the window (but not cover the glass), basically giving a wider surface onto which to attach the casing. There is just enough room for the 2 1/4 inch trim to fit and clear the corner of the crown. We mounted the crown so the top of the it would line up with the top of the casing. Here is another angle of the other kitchen. To me it looks like they took the wide casing all the way up to the ceiling and that the top of the crown covers a little corner of it. [Traditional Kitchen[(https://www.houzz.com/photos/traditional-kitchen-ideas-phbr1-bp~t_709~s_2107) by San Antonio Kitchen & Bath Designers BRADSHAW DESIGNS LLC

Depends on the style of the home but I usually use Sherwin Williams trim paint as it comes- it is just a clean classic white (that can always be matched since it is off the shelf) I have satin trim and matte walls.

Egg and dart would not be used on a vertical surface in any case. I lived in two Greek Revival houses (built c. 1830 and 1840) and they had egg and dart or lamb's tongue moulding as part of the pediment at the top of the major doors and 1st floor windows. It's a Horizontal molding. More or less like this, although my house more strictly followed the Order. It probably sounds pedantic to say the moulding should only be used a certain way, but it really only looks right as part of the proper assembly of pieces. Usually once you drop the capitals, from the assembly it's less common to see the egg and dart as well and it would more likely a cyma molding which looks a lot like the typical crown molding we use a lot now.