The good news is, you got practice showing your apartment and working on your sales techniques, maybe even sparking a new idea.  

I am wondering what techniques and methods did you all use to make your multifamily sales as smooth as possible?

Some of the techniques mentioned just temporarily mask the smell.

But if you self-manage or use a boutique mgmt company that tailors their marketing to each individual property, hopefully you'll do ok through the dip.

Be upfront about parties not being allowed and tailoring your listing to pick up better guests.

You will have to be tailoring each agreement by state.Like @Tim Herman said, you will need to have some kind of license for each state where you manage.

I'm also interested in learning more about creative financing techniques and lease-options.

I want to wear gorgeous tailored suits and show exceptional properties like I've dreamt of so I joined with a company that could do so and mentor/teach me the ropes my mentor currently has a dozen multi million dollar listings.

There were so much damage to the building as each unit moves out, water pipe in the basement was cut and stolen, so bad that I kicked everyone out and did remodel (convert to smaller units) and tailor the building now to higher end clients

Google is tracking everything you do and then posting ads that are tailored to your searches.