If you're doing tile or stone floors, work on picking those materials at the same time as cabinets, backsplash and countertops. The relationships among these materials is critical. It's tough to mix different types of stone and tile unless you want your kitchen to look like a showroom.
Picking bar stools and tables and chairs for an eat‐in kitchen usually comes at the end, but this is also important, so don't just mail it in at this point. Think about adding patina and texture through vintage pieces if you can find them. And don't forget about items like decorative plate racks, artwork and area rugs or runners. Small touches like this can add much character to a newly remodeled kitchen.
I recommend that clients select appliances and sinks during the preliminary design phase, which often comes before selecting the rest of the finishes and fixtures. This is so the plans can reflect the proper sizes, which will in turn affect the cabinetry layout. Also, I recommend picking the type and amount of lighting fixtures during this phase: cans, semi‐flush mounts, how many pendants over the island and so on, in order to complete the lighting plans so the contractor to provide estimates. Most people haven't actually picked what style pendant light yet, but at least the decision about number is done.