I have been a freelancer on Upwork since May of this year. Applied to many jobs but got rejected. But I take it positively as I believe that being patient will find positive outcomes out of negative setbacks. So, as a freelancer here are some tips for new colleagues for their future endeavors.
Patience is a virtue: You have to be very patient until you get your first job. Sometimes it may take a day, month, or year. Meanwhile update your profile, and cover letter, and gather experience with new tools. Go through the new job posts to understand what the clients want.
Read the Upwork guidelines: Must go through the Upwork terms and conditions or guidelines to save yourself from scammers and losing your account on Upwork. Please take the Upwork readiness test. You will get 40 free connections if you pass the exam and also get a clear idea of how to work on Upwork.
Ghost clients: Don't apply for "payment unverified" jobs. I categorized them as "Ghost" clients. Apply to the payment-verified client's job, it may award you the first job on Upwork.
Never share your personal details: Some clients might ask for your mobile number, WhatsApp/skype number, and emails, and might offer you a lot of money if you work with them outside of Upwork. Please avoid these types of clients. Never share your mobile/Whatsapp/skype/emails with a client in the Upwork message box. Eventually, you will lose your Upwork account. Remember, who is going to guarantee your money if you work outside of Upwork?
Escrow is Guarantee: Escrow is there to safeguard your money. Do not start the job until there is no contract offered from the client and there is no money in the escrow. When a contract is offered by a client money will be in the escrow.
Always read the contract details: Always read the contract and job description before you start any job. If you find any changes, communicate with the client, and don't start the work until you get a satisfactory reply. If you ignore this you might get into trouble later on.
Communication is a must: Always try to get opinions from the client on the job. Submit your sample work to get the client's feedback before submitting the final work. Even if the client is slow to respond, you always communicate with the client to get opinions. You will be in the upper hand while you submit your job. Later on, the client will not blame you for a "lack of communication".
Finally, I would say follow the Upwork guidelines to be successful on Upwork and you must have conviction towards your goal to achieve your dreams.
