Forging is a term that you'll probably recognize. In an era where ingots may not have been that uniform, it was needed. Forging probably has something to do with wootz steel - something I know less about, but comes to mind as there is a patterned lack of uniformity in wootz leading to legitimate "damascus".
When you watch TV, if you do, or you see blacksmith demonstrations, what's interesting is the forging and shaping, and perhaps heating steel and plunging it in something and then dumping it out onto a table.
Cutting and shaping (grinding) for almost anyone is going to yield a better result. Bar stock is now the most common thing you'll find - flat bars, for example maybe 0.1" thick and 2.5" wide and 36 inches long. if you're making a plane iron to replace a stanley plane iron, you don't need to do much.
Sentiment on blacksmithing forums and TV shows (forged in fire) is there isn't enough interaction here, but fine spheroidized or annealed steel stock that's been carefully rolled has been forged directionally. The grain is in line, and if you're making knives or chisels, it's biased so that forces bending laterally or snapping an edge off, for example is harder to do.
It is not automatically true that additional forging will improve the result, and if you are new to heat treatment, the chance is close to zero.
heating to forging can introduce cracks - you've seen that, I'm sure. Forging temperatures also grow grain, so quick high heats after forging and then quenching leave large grain and they change some other properties about what goes on during heat treatment.
More importantly, significant forging can result in carbides that are neatly arranged at grain boundaries, or that are tubular but small in the grain direction of rolled stock to go away from their round or tubular forms and create layers in grain boundaries. These layers can reduce toughness if the steel is just forged and then quenched and tempered.
I have had two forged items show tiny cracks - superficial, but to me and should be to anyone - unacceptable. They are almost too small to see at some surface polish levels. If I were ever to offer chisels to a friend even for free, I'd keep those two, so those two are mine and probably will just eventually be thrown away. I also know what I'm doing, and perhaps that's two out of 60.
George Wilson relayed to me long ago that his first set of marples chisels (old enough to be legitimately hard) was bought new middle 1900s, and one of the larger chisels at some point just let loose and lost an inch. I would bet that was a forging fault.
In order to deal with forging faults, and just forging normalities, you need to have first mastered consistent hardening and tempering of steel that's already in a suitable condition just to heat, quench and temper.
How good can "boring" steel be? In 2019, we had a string of posts here about testing plane irons. My house made O1 iron for statistical purposes matched hock french irons that were harder than it was by 1.5 points (courtesy of the hardness tester in house now!). The actual test results came out in favor of my iron. it wasn't that I did something that great, it's that the steel itself - starrett O1 - lends itself to being heated and quenched and tempered with a single temper. This steel adheres well to the simple process - have a heat source with control and hotter than you need it to be, heat the steel until a magnet doesn't stick and then as quickly and evenly as possible, heat the steel for another 10 or 15 seconds with the color shade increasing a shade from nonmagnetic and get the steel in the quench then. The results are world class.
In the knife world, forging faults are encountered with some regularity in O1 because O1 will partially air harden, at least that is what I would guess. I've forged a few O1 items and had no problems aside from the fact that when it cools, it's certainly not as soft and workable as you'd like, but I knew of the advice about keeping O1 relatively hot while forging. The properties gained with my experience (which is skilled amateur, but with hand and eye heat treatment, there's not too many skilled pros) forging plane irons out of round bar or fully forging chisels are not something the average user would even notice. And there are definitely cases where I wouldn't, either.
So, consider forging when you've gotten bored with success. And when you do, understand how to normalize and then refine the grain size of the steel with repeated low temperature heats before finishing off the process.
Now that Clifton is no longer making forged irons, Brent Beach's images from eons ago in a plane iron test always left me scratching my head. Clifton's irons did not match hock or Steve Knight's iron. It's one iron each, so there could've been an issue that didn't occur with other Clifton irons, but I always wondered if the issue was created by forging and then not solved in subsequent steps. It could've been something else, all the way down to supply.
If you start with steel that lacks uniformity in a snapped sample, it's likely that even if you do significant forging, those problems will remain. That points back to the suggestion to buy good stock - if there are problems created at the mill, you are very unlikely to ever solve them no matter how big your hammer is.