Most refusals we see are a missing bank statement, not a problem with the traveller. Here is the pile of paper, in full.
People assume a visa refusal is a judgement on them. Almost always it is a judgement on the file, and the file was short of one thing.
For most of the region you need a passport with six clear months on it, photographs to the exact size the mission asks for, three to six months of bank statements stamped by the bank, a letter from your employer with your salary and your leave dates on it, your confirmed flights and your confirmed hotel. Every item on that list is refused more often for being the wrong format than for being absent.
The bank statements are where it goes wrong. A screenshot from an app is not a statement. A statement with no stamp is not a statement. Going to the branch and asking for a stamped set takes a morning and saves the whole application.
If you are self employed, the employer letter becomes your business registration and your own statements, and the mission will look harder. Build in an extra week.
Bring what you have to the desk and we will check it against the list in front of you. That check is free whether you book the trip with us or not.