You kind of apply the basic SEO rules for on page optimization, but the most important things from my experience are:
1. Reviews. If you can afford it, just buy some and hide the income with a Pro account.
2. Prospecting. Connects are not free anymore, so spend time choosing the right people to outreach. Look for those that you can impress somehow.
3. Use a sniper approach in your outreach. The CV and pre-maxe presentations don't cut it. Get straight to the point, no fluff, tell them what you can do for them and what you want in return. Clients use Upwork to save money and TIME.
One thing I did, but years ago, was to get a low-paying data entry job and outsourced it to a VA. I made literally zero revenue, but it was a hourly project that went on for months and which eventually granted me the top rated status. From then on I started getting leads on autopilot.
But that was when things were a bit less competitive. Now I notice that the new tiered rating system and sheer number of freelancers on the platform made things way harder than before, so it'll take some time unless you're in a micro niche.
This is just from my personal experience, so it may apply to you or not. In any case good luck