This formula (the Gordon growth model), doesn't really apply here, cause the g is for perpetual growth. For example, if you plugged in FB's current growth rate, it would blow up to something ridiculously large. The rule of thumb is that it should never be larger than GDP (since that company would quickly come to dominate the national economy). Tracking inflation is safe if the company can at least raise prices to match inflation.
If you don't want to set up a full DCF, the Benjamin Graham formula gives a quick intrinsic value estimate:
V = E * (8.5 + 2g) * 1.1,
E is earnings (FCF, or a modified form like owner's earnings would work also), but here, g is the growth rate for the next 7-10 years.
This still wouldn't work for TWTR, since negative earnings always give you a negative value, so you would have to project out the next few years until twitter has positive earnings (or positive FCF), then you could use the Graham formula and discount it back to present value. But at that point you might as well just do a full DCF.
If you literally just want the technical stuff, then anything by Damodaran is good. His Valuations book is awesome, but does not qualify as "condensed / quick". You can also watch his valuation course on YouTube.
I have not read it, but if his "Little Book" is indeed a condensed version of his main book, then its a good start. I think he also gives out a PDF for free on his website.
I would advise against blindly applying DCFs, or at least making real investment decisions from blindly running one. When I first got started I looked for some grand "insert and crank" method of valuation, but now I am convinced there is no shortcut aside of thoroughly understanding a business and its financials.
If you don't want to set up a full DCF, the Benjamin Graham formula gives a quick intrinsic value estimate:
V = E * (8.5 + 2g) * 1.1,
E is earnings (FCF, or a modified form like owner's earnings would work also), but here, g is the growth rate for the next 7-10 years.
This still wouldn't work for TWTR, since negative earnings always give you a negative value, so you would have to project out the next few years until twitter has positive earnings (or positive FCF), then you could use the Graham formula and discount it back to present value. But at that point you might as well just do a full DCF.