Here are some tips for improving Evee renders in Blender:
Upgrade your GPU, to improve the render speeds and quality.
Enable Screen Space Reflections, to improve the quality of reflections in your renders.
Use high-quality textures, especially for materials that have reflections or translucency.
Increase the number of samples, to improve the overall quality of your render.
Enable Ambient Occlusion, to give depth and realism to your renders by simulating the way light is absorbed by objects and the shadows they create.
Experiment with different lighting setups and adjust the intensity, color, and position of your lights to get the best results.
Use depth of field, to add a professional touch to your renders and draw attention to the subject of your scene.
Use bloom, if necessary. Bloom allows a better sense of what the actual intensities of the pixels are.
Remember that the best way to improve your Evee renders is to practice and experiment. Keep trying new things and learning from your mistakes and you'll soon be creating stunning 3D renders with Evee!