Well... the buds look perfect since they are the "flowers" of your cultivars. Now if your question is "where and when do the pistils appear?" ...that's another question. The pistils that will later be an integral part of your buds start appearing in autoflowering strains, and depending on their genetics and if you're growing indoors, they will show up around the 4th week (it can sometimes be at the beginning of the 3rd week, or in other cases after the 6th week). So, the pistils that undoubtedly indicate you are in the flowering stage will depend on many factors. In autoflowering strains, generally, the genetics determine the longer or shorter vegetative phase; if you're in photoperiodic strains, as long as the days are shorter outdoors or if you change the light cycle to 12/12 (light/dark) indoors, the pistils will appear in a few days, and you'll start flowering.
Then there are strains and strains... I've had strains where the pistils are very abundant in the buds, while there are others that are mostly made up of short sugar leaves and half a dozen pistils, and when I say half a dozen (I literally mean half a dozen). I've had a cultivar that, for me, is the "ugliest" and strangest plant of all the plants available on the market today. It's a Sativa called Dr. Grinspoon, and its bud structure is one of the strangest you could ever have. The buds are typically either more robust and dense Indicas or more airy and elongated Sativas (with more pistils), but the Dr. Grinspoon is the strangest of all the strange things that exist in the commercial cannabis world. It's a cultivar with very long branches, with very little leaf density, and the buds (they're not really buds but rather small clusters of very short sugar leaves, and the "buds" (if you can call them that) don't reach 5 cm in size. The smoke from Dr. Grinspoon is very good, very psychoactive, and it gets you high without leaving you couch-locked, so it's great for smoking throughout the day, leaving you in a good mood and ready to tackle all the tasks you want... it's a smoke that allows you to smoke and go to work without any problems. But when you can, take a look at the Dr. Grinspoon from Barney's Farm, and you'll see it's the most original thing you've ever seen.
On the downside, it has a problem with its very low yield, and for friends who buy it, it will be very strange to see the type of "weed" that comes from the Dr. Grinspoon. But this whole cannabis genetics thing is incredible, and sometimes planting something different from the norm also has its charm. A strong greeting and "Green greets" to you, my friend.