And we basically went into Season Three with a couple of models in mind in terms of, on the third season of Everwood, Greg [Berlanti] brought in Scott Wolfe and really shook up the show. Third season of Buffy, Joss Whedon brought in Eliza Dushku and really shook up the show. The idea of a new character [Ray Palmer] coming in and being a change agent for a set ensemble was very appealing to us. That was one parameter. Another parameter was that we had Felicity and she sort of, from a dialogue perspective, lives in a different world than everybody else. We’ve been saying that Emily from a witty banter perspective has been playing tennis against the wall and we wanted to give her a tennis partner.
Arrow Executive Producer Marc Guggenheim | ComicBook.com 09/21/2014
Well, I think it’s safe to say that this year is going to be a battle for Thea’s soul, so it’s not necessarily going to have a happy ending to it. Certainly there is the potential in her name and we’ve been calling her “Speedy” since the pilot, but one of the things that we like to do is play against that expectation. So hopefully the ups and downs of Thea’s arc this year will be compelling but also surprising.
Arrow Executive Producer Marc Guggenheim | ComicBook.com 09/21/2014

#16 | BLACKHAWKS & TED GAYNOR

In Season 1, episode “Trust, But Verify” the Black Hawk Squad Protection Group is a DC Comics “easter egg” for The Blackhawks, an international paramilitary group of pilots operating against the Axis powers during World War II.

Also, Ted Gaynor in this episode is a reference to Lt. Theodore Gaynor, a member of the team from the 1980s series. He was a former Blackhawk turned villain in the comics. Gaynor briefly appeared in the original series but his attitude and sense of entitlement caused him to be ousted of the group.

100ArrowDCComicsEasterEggs | 16 days until the premiere of Season 3

Source: dc wikia

I think people will be very happy with Laurel’s trajectory specifically this year in that regard. She’s going to start trying to walk the path that her sister walked, which is something we set up in the Season Finale and I think people are going to be really excited to see where that goes.
Arrow Executive Producer Marc Guggenheim | ComicBook.com 09/21/2014
Sara’s back. Caity Lotz is in a recurring role. We’ve made a deal for three episodes but at current count, we’re going to have her in for five, at least. Obviously with all of our recurring cast members, we always have to work around their schedules but we love Caity. We have really cool plans for her.
Arrow Executive Producer Marc Guggenheim | ComicBook.com 09/21/2014
Season One had a really cool, over-arching mystery. You had the glyph, you had The Undertaking, you were kind of wondering what was going on. There was what we called in the scripts the Well-Dressed Man, who turned out to be Malcolm Merlyn. And we wanted to basically take the epic quality of Season Two and fuse it with the mystery of Season One
Arrow Executive Producer Marc Guggenheim | ComicBook.com 09/21/2014

#17 - BLACK CANARY COSTUME

In Arrow, the Canary’s costume doesn’t use her signature fishnets, although there is a glossy criss-crossing pattern over her pants.
Designer Andy Poon explains:

"For Black Canary, I’m just waiting for people to flag that she is missing her signature fishnets. So if you haven’t noticed, I implied the look of the fishnets with cross leather straps on her pants."

The costume also features the jacket, the wig and the big cleavage

100ArrowDCComicsEasterEggs | 17 days until the premiere of Season 3 

Source: Andy Poon Blogspot

SHERWOOD FLORIST || DC Comics

When Oliver Queen and Dinah Lance moved from Star City to Seattle, they lived in an apartment above Dinah’s flower shop, the Sherwood Florist - a play on Oliver’s Robin Hood influence. The ground floor was the shop itself, while the second floor was Dinah’s living space, and the third floor was Oliver’s. The florist served as the base of operations for both Black Canary and Green Arrow for the duration of their residence in Seattle.

The shop’s name is a play on the “Sherwood Forest”, the home of Robin Hood, who was a significant inspiration to Oliver Queen in the creation of his Green Arrow persona

Source: dc wiki