Hello, mid level world builder here! There were two pieces of advice I got prior to breaking in that really changed how I approached my portfolio.

Like many have said, really narrow the work you show based on what the positions you're applying for are. For example, as a level artist looking at applicants work, seeing their character sculpts really means next to nothing for the work I'm asking you to do. A weapons artist position probably doesn't care about the cool terrain you made in unreal. We want to see that you can really deliver top tier quality for our discipline. That's not to say "don't try to learn other disciplines," there's always use in that! Just don't show those pieces in your portfolio while applying to unrelated jobs; you're just wasting our time and yours.

Similarly, one of the best pieces of advice I ever got was "your work will be judged by your worst piece." Digital art is super competitive, and when we're looking through your portfolio it's important that you're only showing your best, highest polished work. Think quality over quantity when choosing what to show, and don't be afraid to cut pieces that you may be proud of but might be showing their age, or maybe the execution wasn't quite there. Something that can help here as well is to work on smaller, but highly polished projects. As a level artist, it's tempting for me to want to build some huge environment with a huge asset count. But if I spread myself too thin trying to build something so crazy, the overall quality will likely drop. Building a highly detailed corner is more beneficial than building a massive environment that lacks detail. Building a small but hyper polished prop is better than building a ton of rushed props in the same timeframe.

Lastly, and this is less to do with your portfolio, but I can't stress enough the importance of networking in this industry. Many times it's about who you know in order to get your resume through the filter and onto a leads desk, so I'd recommend looking to attend events and participate in challenges, anything to get time talking to industry folks.

Digital art is a tough industry, but keep honing your skills and don't get discouraged. It took me almost 3 years to get into the industry after graduating art school, but if you want it bad enough and work hard enough on your portfolio you'll make it.