Last but not least, practice more.
Practice your calligraphy carefully. After writing 50 gel pens, I promise your handwriting will improve.
Mitsubishi UMN- 152 is recommended, which is cheap (online shopping can't reach 6 yuan) and the refill is not expensive (one from 2.8 yuan, durability 150% made in China), and it feels comfortable. Mitsubishi UM- 15 1 can be considered for the cap drawing pen. The style is similar to that of True Color 009, but once you use it, you will find that the quality and feel are really different, and the price is not expensive, four or five yuan each.
Anyway, the quality of pens is high, and the characters are generally better.