Reddit reviews Spill Stop 285-50 Chrome Tapered Pourer Dispenser Spouts with Poly-Kork, 12-Units

I'll just go ahead and list a few of the things I use on a regular basis.

Koriko shakers are awesome. They look cool and function amazingly. Good investments. End of story.
http://www.cocktailkingdom.com/Koriko-set-of-2-Weighted-Tins-large-and-sma-p/sha_korikoxxxx_0028_set.htm

I prefer using a julep strainer over a hawthorne strainer, it works fine for me when I'm not muddling things into the drink I don't want served.
http://amzn.com/B001VZAMPQ
http://amzn.com/B000H7VF64

Get speed pourers. Even if you don't plan on free-pouring, they're nice to have a more standardized pouring speed so you can pour out of an entirely full bottle without worrying about spilling too much.
http://amzn.com/B002J8RRAM

A cheap bar spoon is an awful experience. A decent bar spoon is fine. An overpriced barspoon is (generally) just overpriced metal. However, the Tanqueray spoons and the Standard Spoon on kickstarter are actually pretty nice quality stuff. But that said, almost everyone I've met likes the regular old bar spoon.
http://amzn.com/B000VQOP5O
https://www.kickstarter.com/projects/workofmyhands/standard-spoon-for-craft-cocktails

Have a jigger on hand, even if you free pour. Just for when you have nicer ingredients and want to try out a drink with them and would rather have the proportions right than have to revive the drink.
http://amzn.com/B00080B07Y

I make a lot of bitters myself or super small batch infusions, so having a set of mason jars on hand has been extremely helpful.

I use cheapo squirt bottles ( http://amzn.com/B007OM9W2E ) to store simple syrup or other infused simple syrup.

If you get super into infusions and stuff like that, I've heard a lot of good things about the iSi system; I have a friend with one, he absolutely loves his. I have to admit, it takes a lot of work and patience out of infusion. As well as whipped cream, or carbonating things, or what have you... now I might want to get one.

These two items are somewhat paired (at least for me) -- a water filter and an ice tray. For ice, I'm talking like the Tovolo King Size ice trays. Water filter -- doesn't matter, as long as it filters from what I can tell.
http://amzn.com/B00395FHRO

Something that's nice to have on hand so you can double-strain is a fine-mesh strainer. Can be harder to find on the cheap though, I ended up breaking down and going to a Bed Bath & Beyond for mine since everything on Amazon was fairly expensive the thrift shops near me didn't have one.

Get nice glassware. I remember when I was younger and someone demonstrated the importance of having nice glass when tasting wine. The same thing applies. This isn't exactly bar-tools, but it's critical to your cocktail experience. Drinking out of cheap glasses, or the wrong glasses, will really hurt the presentation and your perception of the cocktail. In essence, t's important to take pride in both how you make the cocktail and how you serve the cocktail.

That's all I got for now.

I guess it varies slightly model to model. I mostly see these https://www.amazon.com/285-50-Chrome-Tapered-Poly-Kork-12-units/dp/B002J8RRAM/ref=sr_1_1?ie=UTF8&qid=1482344242&sr=8-1&keywords=spill+stop+pour

regardless you learn the count of pouring 1 shot with whatever pourer you use, and then just count

These seem to be the most preferred speed pourers by bartenders and beverage directors I've interacted with. I seldom have an issue with bottle fitment, except for Patron and other similar bottles. They ain't cheap but worth every penny to me.