1.) Join local writers' groups and/or online writers' groups. (Just do an online search to find suitable ones). Their feedback will give you good perspective.
2.) Consider hiring a (reputable!) editor. There are tons of great experienced freelance editors, just be careful to not get scammed. I know people say "don't pay to get your book published," but again, the feedback can be very valuable.
3.) Attend local writers' conferences. You can bypass a lot of the "faceless submitting" by talking to editors and agents face-to-face.
4.) Send out your manuscript to agents and publishers. I prefer to use the above steps to make connections, but this can be a good back up. Just do some online research to find publishers and agents who are accepting submissions. Writer's Market is a good source for some of this information. You can also look at the publisher info in books you've read in your genre, and then look up those companies online.
5.) Cultivate an online presence. Getting yourself known online with articles and building up a social media presence will help your chances. Nowadays, agents and publishers want someone who will share the load of marketing.
Hope this helps!