Besides all of that, you need to have your logo in vector format. Raster graphics are not suitable for large-area surfaces, such as billboards. When zooming in, you will get a fuzzy mosaic image consisting of squares. No advertising agency will undertake the production of a layout after seeing a file in .psd, or, even worse, in .jpg.
The selection of primary colors is also very important here: you should be provided with a selection of colors at least in RGB (used for the web) and CMYK (for printing). Colors don't have to live their own lives after the final approval. If a certain color is used in the logo, then it should remain so. All kinds of deviations and shades should be clearly spelled out in the brandbook, otherwise the corporate identity will simply not be readable in the future.
On average, the corporate identity becomes obsolete in 5 years. Yes, it sounds sad, but let's try to make sure that your logo remains relevant at least for this time, So that you don't look at it in a year with the thought “and why did I pay so much money". Logo design development should not turn into a race for trends. Your logo should be relevant, not trending. See the difference?
The font should convey the spirit of the brand. For children's clothing and for a law firm, the choice will be different. And it definitely doesn't mean “something cute”. Unusual fonts are an unfortunate choice. You will have to adapt the logo for signage, social media accounts and websites. Text should stay readable. Two fonts are often used in the corporate style: one for logo and title, another one for the rest (letterheads, long texts and so on). You don’t need to use artistic font everywhere or randomly add another fonts - limit yourself to two.
Overloaded logos are more difficult to use. They become obsolete faster and bother potential customers. Look towards healthy minimalism - such a logo design will look organic and be well remembered. In addition, the meaning of the main elements will not be lost.