Adaptability
At the end of the summer season, depending on the region you live in and the vagaries of the weather, the blackberries are more or less fully ripe. An opportunistic fish by definition, the chub adapts to what nature provides and makes it its main diet as long as the blackberries are willing to fall into the water.
The angler's first approach will be to observe the mulberry trees overhanging the bank, and in the case of mulberries still present in the brambles, this is the best place to start. Be careful, however, to check mulberry bushes in several locations, as their ripeness may vary according to exposure.
The angler will need to select a few ripe baits, as chub have little interest in fruit that is still red, bait it on a single, wide-mouthed Wacky-style hook, size 6 to 2, and present it near a bramble. The curious chub will often be attracted by the sound of a blackberry falling to the surface and pounce on it.

In case the blackberry season is already over, there's the alternative of artificial blackberries. While it's honestly very practical to have them on hand and not end up with purple fingers at the end of the day from luring real blackberries that are lost at every touch, the truth remains: blackberry bait works best when the blackberry bushes are full of them. Out of season, it's best to turn to other small berries of the moment, or to insects, for example.
The return of decoys
As the season progresses, bays and other small fruits falling into the water will become increasingly rare. Chub will begin to change their summertime frugivorous habits to seize more small fish or insects.
If the water is still warm and clear enough, chub will be slow to leave their surface position in search of insects falling to the surface. They can therefore still be stalked by sight as you would with fruit, but this time we'd rather use surface insect imitations such as the famous Woodloose (Illex) which has the advantage of presenting and retaining attractants well, but whose major drawback is that it is light and difficult to cast, weighing just one gram. In the same spirit, you'll also find the Notobug (Sakura) in a hard lure version, formidable in its 1.5 and 3.5 g versions.
Small swimming fish can also be very attractive, mainly to compete for food. A small crankbait like the CRK30F (Caperlan) slowly reeled in sub-surface can wreak havoc, while micro stickbaits and small poppers, more aggressive on the surface, will be less attractive than in summer.
Once the surface is well prospected, it's a good idea to present a few insect imitations or small soft lures between two waters, like a dragonfly (Fishup) for example, to be left drifting for a few metres without too much animation, the fish generally observing its prey before discreetly gobbling it up.
Larger specimens can be decided by working with small, slightly deeper lures such as a silent crankbait like the Assault Crank (Fishus).

In terms of equipment, a UL (0.5-5 g) or L (3.10 g) power rod with a length of 2 m to 2m20 is ideal. A reel size 1000 to 2000 fitted with 8 to 10/100 braid prolonged with 18 to 20/100 nylon or fluorocarbon will enable you to respond to all situations and maintain control during fights.
A little deeper
On fairly deep spots, or in the case of an early autumn, the fish will prefer to stay in the water layer, or even directly on the bottom.
If the water is still fairly clear, sight-finding can be carried out, but will still be more complicated. Many types of lures can then be used to descend into the water layer, such as larvae or crayfish imitations mounted with 1 to 3 g leaded micro heads or a small N°0 or 1 spoon to be brought back slowly.
The chub will often attack on the way down or after the lure has first jumped to the bottom with characteristic violence, so it's best to stay in contact with the lure at all times for a fast, sure strike.

The red thread: the approach
Whatever the season or the weather, since chub have a wide field of vision and react to every movement on the bank, anglers should opt for a very discreet approach, keeping their distance from the water's edge when prospecting. While a good pair of polarized glasses is part of the chub angler's essential kit, flashy clothing colors are to be avoided and approaches should be made in the shade of trees without making any sudden movements, at the risk of seeing the fish scurry away at lightning speed.
Beware of noisy casts too, and leave the skipping to youtubers or black-bass anglers - be quiet, enjoy.