A feeling of inclusion (or exclusion) begins at the point of hire. Those who staff classes and hire part-time faculty know that there are often cases where a last-minute change is made, leaving a class without a professor and leading to hiring someone at the eleventh hour. When we talk about hiring last minute, usually we complain about the "quality" of faculty who are able to take on jobs right at the start of a semester. They are often new, with no teaching experience at all.
There is, however, another side to the topic that isn't considered nearly as much as it should be. Part-time faculty hired at the last minute miss out on orientation and other beginning-of-the-semester professional development activities and meetings. They start on the outside and often without important information that they need. They miss out on the opportunity to meet other faculty members (full- and part-time) and administrators and network with them.
Obviously, last-minute hires should be avoided whenever possible. One method of avoiding last-minute hiring is keeping a database of potential instructors who have already been vetted and perhaps taught in the department previously. One way to accomplish something like that is to keep in touch with adjunct faculty who take a semester off or fall victim to class cancellation. These faculty members should still be included in department activities, invited to meetings, and encouraged to attend professional development activities at the college.
However, when last-minute hiring cannot be avoided, there are some things we can do to create a sense of inclusion. Interview processes are different depending on the institution and who is conducting the interview. However, all potential adjunct faculty, no matter when they are hired, should be put through a standard interview process that in some way approximates what is done in interviews for full-time faculty. For example, many institutions require a teaching demonstration when interviewing candidates for a full-time position. Adjunct interviews should require something similar; they should be asked at least to walk the interviewer through a lesson. Since I oversee an English department, I also ask potential adjuncts to score student essays using the department rubric and then explain their reasoning for the score they give. I conduct interviews the same way each time, even when I hire at the last minute. It may sound counter-intuitive, but part-time faculty who are hired based on a rigorous interview will feel that they belong and are truly wanted, rather than being hired out of desperation.
When we do hire last minute, we need to do what we can to make up for missed orientations and meetings. They should be given a handbook with pertinent information about the department. It might also be a good idea to have a short video series that can serve in place of a live orientation. While the networking and discussion opportunities may still be lost, videos are an easy way for new hires to get pertinent information quickly. And, let's face it, we are all more likely to watch a few short videos than read a handbook, especially if we have only a few days to prepare for the semester.
Finally, special trainings and/or meeting sessions should be held very early in the semester for people who missed out on orientation sessions. There they can meet senior faculty, do a little networking, and ask whatever questions they have early on. Availability of senior members of the department is crucial to a sense of well being and belonging.