The adjustments you need to make to your application depend on the reasons your mark is ineligible for registration.
For example, if the issue is descriptiveness, registering a figurative trademark (logo) instead of a wordmark is often the most practical fix. A logo incorporates visual elements that add distinctiveness beyond the words alone, which can satisfy the examiner and reduce the likelihood of opposition from existing mark holders. However, it's important to keep in mind that the logo's visual elements must be sufficiently distinctive to make a genuine difference; simply stylizing a descriptive word is unlikely to be enough.
On the other hand, if the issue is similarity to an existing mark, options include narrowing the goods and services list to avoid the conflicting class, negotiating a co-existence agreement with the owner of the earlier mark, or modifying the mark itself to increase the distance between the two.
Find out what's preventing your trademark from registering with a free lawyer's check.