It depends on which style you want to develop!
The following are the tools I used when I was studying illustration at Wuhan Illustration School. You can give the poster a reference
1. Adobe Photoshop
1. Pens and brushes , common tools for painting, brush definition 2. Mask application, adjustment and change 3. Use of filters and channels 4. Effects and adjustments, 5. Post-processing
2. SAI: Common tools for digital drawing It is a kind of tool that has very smooth lines and is easy to use. It mainly learns the application of lines and colors. Generally, it is often used in Japanese and Korean style illustrations
3. Painter: It is a digital sketch and painting The ultimate choice of tools, this is an excellent natural painting software with comprehensive and realistic natural brushes. It is specially developed for digital artists, illustrators and photographers who desire to pursue free creativity and need digital tools to simulate traditional paintings. It can replicate the effects of natural media through digital means. It is the best product in its class and has been unanimously praised by the industry.
The most common one is Photoshop sai ps pt. If the drawing is convenient and simple, use SAI. But if you are a novice with poor foundation, I suggest you use PS. If you have good skills, you can try Painter. PS and AI are not reachable, and there are many people (Painter, PS) who use both together. The effect will be better.
Chinese style illustrations
Domestic web game style