Although interior work is my least favorite, the "typical" client seems to appreciate it more then exterior work.
You did a great job. I bet the client was happy with your work as well.
I agree.
By far a smokers Interior is the hardest to clean. You have the smell, tar discoloration etc to deal with. If they want a complete interior detail meaning the works, not just a vacuum and a dust free dash I always charge $50 more. The dust on the dash of a smoke free car will normally come off with a damp MF (occasional cleaner) a brush and a vacuum, while a smokers car needs a brush and APC everywhere. Because of the tar Dust sticks to everything, vents are a pain to clean, it stinks and everything has yellowish tint to it, dust even sticks in the cracks. Carpets have a really musty smell and the headliner is ridiculous due to the smoke rising to it. All of this takes significantly longer to clean so make sure you charge more.
Price is your option-I just figure an hour longer plus added product.
As far as equipment, tools and chemicals go I would suggest the following-some of this is not an absolute must have because some can be substituted for whats already available. Some is more of a luxury for you that will make the job easier and faster.
Vacumm with multiple attachments-long crevice tool, dusting brush to dust in the cracks and suck it out (made my time quicker) works well on leather seams too, a "wide opening" nozzle for carpets. Those are the basics you can get by with. I use a ridgid 5hp 4 gallon portable shop vac with the auto detail bundle. I love it, after shampoo I take the filter out and suck up the leftover shampoo. Vac and attachments were around $130.
Vent brush-this is a multi purpose brush IMO. You can dust and with the addition of APC, clean cracks when needed. You can get one from AG for $3.00 I think.
Soft leather brush-boars hair if you can afford it-if not a soft nylon brush. I don't think you need anything stiffer than that.
Upholstery brush-I like the long bristle because it is not as hard on the carpet. Short bristle tends to cause the carpet to shed (that's the only words I could come up with to explain it)
MF towels, MF applicator for dressing.
Two 3.5 gallon rinse buckets
Chemicals
Good APC of your choice-optimum powerclean works well
Good upholstery shampoo-love CG lightning fast stain extractor-works amazing
Nice drying dressing-currently using CG silk shine and love it
Window cleaner-stoners invisible glass is the best IMO
Hopefully others will add to this because I am sure I have forgotten a couple things. Hope this helps.
Good APC