Most researchers are eager to submit their paper immediately after finishing the write up. Being too excited to get the paper published leads to some common mistakes. After finishing write up and enough revisions, take a break. Celebrate the occasion.
1. Check scope: Give some extra time in finding your suitable journal. If you are not completely convinced by the aim and scope of the journal (in most cases, multidisciplinary journals are confusing), better ask the journal editor/manager to check whether that journal is suitable for your article. Send them your title and keywords. Wait for a day for response. Its always a good practice to check before submitting.
2. Take some time off: Journal article submission is not like sending email. Take your time to register and provide all necessary info. Some journal asks for highlights. Most authors do not write highlights in manuscript preparations. They just types it in haste to submit it quickly. Give some time to write highlights and cover letters to editor. Check all figure files before submitting.
3. Author list: It is vital for all postgrads. Do not submit a paper without consulting your supervisors. If he/she is too busy to read it all(in most cases they are), at least take instructions about author-list. Order of supervisors in author-list could be vital. Some mean supervisor can get offended by your author-list. Its better to avoid unwanted complications with supervisors. Another important issue is corresponding author. Try to get corresponding authorship. Getting your name in first position of author-list can add value in job and scholarship applications.
Happy publishing!