Even though there are no dimensions in ACTUAL reality I enjoy contemplating the infinite intricacies of the illusory special consensus reality I am currently confining myself into.
There is no need to order dimensions in any certain way. A model is always a limited representation of actual reality. But for convenicence, we start with three dimensions of space.
Then, the fourth dimension apart from the three spatial ones is time.
The fifth is the operation of consciousness on time. These operations are the use of memory and planning out the future. Information from the past used to plan the future can be seen as a distance measure of the fifth dimension in the present moment.
To extend this thinking, the sixth dimension is the actual change in projected time-lines as the effect of remembering, planning and executing plans over a period of time.
Other concepts which fits this model is awareness and conscious choice. It is interesting to note that awareness acts like a variable blanket or mapping onto information streams. These streams are typically sights, sounds, touches, tastes, smells, thoughts and other interior senses and emotions. Conscious choice is the director of focus among the streams. It has no actual fixed bounds, but illusory ones maintained by thought and unconsciousness. Among these are awakeness, dreaming sleep and dreamless sleep. These can be included in the model as additional dimensions.