Make new Gmail look like good old loved Google Inbox.
• Smaller font size.
• Better font family.
• Font and background color adjustments.
• More of white space everywhere.
• Dividers between basic sections in left menu.
• Hide unread counts in left menu.
• Hide stars in e-mail listing.
• Hide scrollbars in e-mail listing.
• And much more!
Suggestions, what you should adjust manually in your Gmail settings:
• Set Comfortable or Default Display Density.
• Disable categories tabs, priority inbox and all other such crap.
• Disable personal level indicators, importance markers and other such crap.
• Hide all labels you don't want to see.
Feel free to send me any improvement suggestions to firstname.lastname@example.org!