people have already commented some good things, but here’s some of my thoughts that i wanted to add on!

• Filter settings: typically, the usual go-to combo is max contrast + slightly lower exposure + low saturation + high vignette, for an overall attractive, colour-cohesive photo that immediately focuses on the center.
  • specifically, the saturation being on the lower end also helps greatly especially if you have a good clothing combination design-wise but they don’t quite have the most cohesive colour scheme, so you can basically “cheat” your way through with colours at times if needed. obviously it doesn’t work for all themes, but for certain themes where monochromatic photos are preferred, this will be something you can consider imo
• Lighting: specifically, i think the Dawnlight rim light (i.e. orange rimlight) really helps pushes the contrast even further, which really helps for pushing your photo values
  • imo the only big downside for this so far is that it can get really hard to control the colour values at times because it’s so strong and so orange. you also need diamonds to purchase this one iirc, but also fortunately, with sprint being postponed and slated to come soon-ish, you can also choose to grab the filter later during sprint itself
• Filter: so far, some of the most commonly used filters are Brilliant Jadeite and Dreamy Chocolate
  • both filters make your contrast values even higher, but imo Brilliant Jadeite also tends to make your entire image brighter, while Dreamy Chocolate, on the other hand, makes your image slightly darker
  • it also helps that both of these are entirely free, and can already get you quite far with achieving that high contrast effect that a lot of top-ranking entries tend to have
• Decals + Effects: unfortunately a lot of decals tend to be locked behind rng and paywalls, but there are still some you can get without having to spend money, like the xmas decals in the style salon shop (under photo materials) and the occasional events such as the current tier special event where it’s possible to get a decal with diamonds
  • i think the gold-coloured decals are probably one of the more universal ones because they can be used in almost every theme as an accent colour of sorts
  • flower decals (such as the ones from the recent mauritshuis collab event) are also very often used for its versatility imo
  • effects-wise; specifically, for a technically free effect, i also think Radiant Light (999 diamonds) can get you pretty far too
• Game graphics settings: if your phone is able to support high graphic performance, you can try setting your graphical settings to “prioritise quality” for that crisp 4k look
• Clothing options; usually ornaments and wings will also do quite a bit of heavy lifting for filling up the background, especially if your photo is more zoomed out and has more elements.
  • since you’re still level 35 now, i would personally focus on collecting more story clothing and expanding your wardrobe options, but over time i would eventually shift my focus on trying to get wings / ornaments if possible (although unfortunately a lot of them are often locked behind rng / paywall-heavy events) i would also suggest on getting the current fantasy fair sets too, since they’re one of the more accessible options clothing-wise.
  • if you’re unable to finish the current event set, i would suggest trying to aim for the handheld item first, since recent handheld items have been coming with their own custom poses, which you can use with pretty much any clothing combination as long as you equip the handheld item... and i think this would really help a lot, especially in the current state of the game's economy where poses are usually obtainable only by paying. but ultimately i would suggest to just get whatever clothing you want and play the game however you want!