Need to stop winging it versus the English Opening; Any ideas?

I play 1 ... Nf6 in case White plays 2. d4 so as to be able to play the Benko Gambit, but mostly White plays 2. Nc3. After 2. Nc3, I tend to play the King's Indian Defense but White tends to fianchetto his King's side, which somehow makes the King's Indian less potent (or at least it feels that way in my games).

learn the 1..c5 lines. you don't have to copy everything white does. you can deviate early to get a fight. this is the most consistent with a benko/benoni repertoire.

not much to hope for if you are waiting for white to play d4 before playing c5 as if he plays 1 c4 he's likely not going to enter d4 pawn structures. so if you want to get in your c5 you have to play it on move 1 or hope to play it after say completing kingside development and invite white to advance d5. but by then it would have been more of a benoni type and not a benko.

Against the English I play a reversed Grand Prix which can start 1.c4 e5 2. Nc3 Nc6 3. g3 f5. I seem to get a better game using it than other systems I tried against the English. The Four Knights variation is popular but there's a ton of theory to memorize. The symmetrical English is a bit too dull for my tastes.

The fianchetto King's Indian is meant to slow down Black's attack.  A decent line for Black is the Kavalek System.

1.d4 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 O-O 5.Nf3 d6 6.O-O c6 7.Nc3 Qa5.

Now if 8.e4, then 8...Bg4 intending 9...Bxf3 and 10...e5.  Against slow moves like a3, 8...Qh5.  The Queen trade gives Black no problems if that happens on d1.

Via the English move order, that would be 1.c4 Nf6 2.Nc3 (or 2.g3) g6 3.g3 Bg7 4.Bg2 O-O 5.Nf3 d6 6.O-O c6 7.d4 (7.d3 gets White nothing!  7...e5!) Qa5.

#1
"I play 1 ... Nf6 in case White plays 2. d4 so as to be able to play the Benko Gambit, but mostly White plays 2. Nc3. After 2. Nc3, I tend to play the King's Indian Defense" So you have to upkeep 2 openings: Benkö Gambit and King's Indian Defence. That is not efficient. If King's Indian Defence is fine for you, than why bother with Benkö? If you want Benkö, then why allow transposition to the King's Indian Defence.
"White tends to fianchetto his King's side, which somehow makes the King's Indian less potent" That is not the case. The most testing against the King's Indian Defence is the Mar del Plata main line. Korchnoi for example played 1 c4 hoping to transpose to the King's Indian Defence and avoiding the Grünfeld: 1 c4 Nf6 2 Nc3 g6 3 e4 Bg7 4 d4.

I've played 1...f5 a bunch, and you almost always get a better Dutch setup than you normally would since English players seem to be scared of playing d4. But if you're not into Dutch structures, there's a pretty good Chessable course that I've been studying ("Reversed Sicilian") based on 1...e5 then following up with c6 and d5, which you might check out. 

There are so many possible luines  after 1. c4 Nf6 2. Nc3 that you really need to decide what you are looking for: a super solid position where white has to take risks to have winning chances? a system with many possible twists and turns so you have a chance to move-order white? a super aggressive system with a closed center and king side buildup? a system that challenges the center right away?  I dont find the English hard to play against at all but you do have to pick something and not drift for a few moves as then white seems to get a lot of pressure from no where.

Generally I just go e6 d5 and open it up.

English defense

and this line

and this

Aren't the forums for the opposite? I.e. this is where you ask for things you can use to "wing it."

If you want to actually learn an opening then you have to study something... no one is going to post a book's worth of info in the forums.

Jaenisch Gambit with 1.c4 b5!