We shared my status docs in canada, my salary slips and bank certificate as i mentioned i will support my wife during her visit. For my wife - her employment docs (offer letter, salary slips, tax docs), marriage certificate, her savings account. That was most of it.
I would say write a really strong invitation letter giving a really good reason to invite your spouse, for example - wedding anniversary, or a birthday (provide bookings for some small party or travel plans if possible, although we didn't provide anything) etc. Also request that you will visit for a short time period of vacation - 2 or 3 weeks max). This would make a really good case considering all other supporting docs are fine.