I was unsure where to post this topic. In level design it will inevitably be overlooked by the target audience and buried by other topics. It is also not a contest even if it's about contests and would clutter the board. As it should be at least a piece of advice/turorial, I think it will fit in well here while at least having a chance to be seen by the target audience.

I recently heard a statement about how again not an easy level won the contest. This is true and even if difficulty depends highly on personal opinion most contest winner levels are on the "medium", "medium-hard" side.
Why is that and how can such a baseline be broken?
Levels usually gain a lot of votes if the solution is surprising (aka uses an old or new trick well), executes smoothly without much fiddeling and if not too strict timings go together smoothly. Also levels that are visually breathtaking tend to gain bonus votes.
Let's take the recent LOTY 2020 winner:
DireKrow's "Shoestring Operation".
It's not an easy level, but not nearly unsolvable. It takes time and effort to solve, but most people will eventually get it. It has a nice distinct look and the execution is not fiddely. I would again put it in the "medium", "medium-hard" range.
If many people solve the level it also helps their cause. As people who have solved the level by themselves tend to have a more positive connection with it.
On the other side levels tend to do worse if they get too hard. Especially the "solution is surprising (aka uses an old or new trick well)" part can easily do a 180 if you overdo it. Often this is unvoluntarily as difficulty is hard to judge.
If people cannot solve your level, they tend to not vote for it even if looking up the solution.
I would raise my contest 17 entries
IchoTolot's "Shadows Of Ourselves" and
IchoTolot's "Catacomb Of Sorrow" as an example here. I would still claim that they are good levels, but only like 1 or 2 people solved them.
But consider this: If people immediately solve your level it can fail to leave a mark and feel empty or just be like whatever.
So how can we midigate this and get far in contests with "easy" levels?Point 1 and by far the most important one: Easy does not imply trivial!It can be hard to achieve and you can easily drift away into harder ranges, but this is important. Easy does not automatically mean that the solution is completely trivial. You do not have to give the player like 99 of everything to make something easy.
You can focus on a smaller level with not so many but easy to place skills for example. A gap over a death pit always means a contruction skill is destined to be placed there, a wall you 100% have to go through forces a destructive skill,...etc.
You still should create a puzzle and not just merely a set of tasks to be done. The "set of tasks" types make good training levels but are not that impactful otherwise.
I would put up "Postcard from Lemmingland" as a positive example or even
zanzindorf's "Bird Knight" which won contest 11. Both levels are not trivial, but should not give you many problems if you are moderately familiar with lemmings in general.
Do not simply throw in dozens of skills and make everything trivial! It is still a puzzle game and if there is no puzzle there it won't stick in people's minds.
I also need to add that having the normal solution be trivial and only introduce more challenging solutions via talismans usually won't be enough and too many talismans can really clutter the level!
Point 2: Score on the visual side!So your "easy" level is not trivial, but that does not automatically make it a hit. If it does not look excellent it will miss out on quite a few potential votes. Visuals alone probaly won't carry a level to victory, but even I can assure you that I had plenty of situations when I gave my vote to the better looking level when I was torn on what to vote. If it does not look good you cannot count on getting good results and if you cannot blow people's minds with complex tricks, blow their mind on the visual side!
Take plenty of time to craft, shape and decorate your contest levels! Don't just slap some things together! You can slap solutions together - I know this works if correctly handled

- but you can't slap landscapes together. Pieces should go over smoothly (or roughly in a fitting way) into each other. The outside of the main playing area should be at least somewhat decorated. Giant walls can have cravings made out of other terrain on top of them to create beautiful effects and as a result they are not giant monoton terrain sections, etc. Make your level look great and you will definitly gain some extra votes here and there.
Point 3: Avoid generally disliked machanics.Be really cautious to not lower your chances by adding mostly disliked things! Easy levels sometimes try to rely on gimmicks and this can heavily backfire in contests!
Avoid things like unnessesary timers, hidden stuff and overly repetitive tasks (near to nobody is excited to build a 20 builder bridge). A few people may like/tolerate these things, but in the vast majority of cases it will cost you votes.
Especially fooling the player with hidden stuff tends to really bring down your vote count.
Do not take this extra handicap!
I hope this has been somewhat helpful and you hopefully have a bit more success with contests now! 
Still, winning a contest often still has a touch of randomness attached to it and do not take winning as guaranteed! Even if you follow these guidelines you won't automatically win, but I would say youer chances will rise!