The reason I do so many card effects when performing is because so many people have asked me to come back to there table and do a few more card tricks or just as I have been about to leave can you do another card trick and so many spectators have said to me they enjoy card tricks the most in magic so thats really why im so into cards when performing.
An Opener is something quick and flashy trick right to grab there attention , normally my first trick I do at tables is jokers wild or some color change routine kinda thing I do.
Normally for closer I use my own effect 4 of a kind or ACR maybe Paperclipped etc.
But my spectators must be having a good time and be enjoying the magic otherwise they would not book me again for gigs also if my spectators wernt enjoying my magic then I doubt I woud be working in the Restaurant anymore and I no for sure people have been enjoying my magic becasue of all the positive feedback I have been getting from people after the gig

but I understand what you guys are trying to say, but from my experience this hasnt always been the best approach.
Here is a link to me performing one of my favourite cards tricks watch this video and decide for yourself if the people im perfoming for are enjoying the magic or not.
http://media.putfile.com/litmus-paper-2