Hi Ellie. Here's the critique you asked for!
Resizing images: This is something you really need to fix as quickly as you can, because it's something that will definitely hold you back from being promoted in the future. +here, the image of Emma hasn't been resized properly so she's become distorted and warped. I can see this issue in a few of your graphics and I'd recommend either redoing or removing any where that's the case, because it's a big issue. When you're resizing images in photoshop, you need to hold down the shift key while you're doing it and make sure you don't let go of the shift key until after you've finished resizing the image, otherwise that's what happens. You've got the same issue +here (far left), +here (Emma and Tom), +here (Emma), +here (left) and +here. This is something you need to be really, really careful of because it will hold you back.
Contrast: Having a good level of contrast means that your graphics, and most importantly the people on your graphics, appear natural. If you don't have enough contrast, they can look pale and washed out, but if there's too much, then your graphics and people look too bright and harsh. +here, your people are under-contrasted and look a bit flat, whereas +here, +here, +here, +here and +here you have too much contrast. Make sure that you only use pictures of people that already look natural and high quality. Otherwise, your graphics are going to suffer as a result.
Backgrounds and textures: As a rule of thumb, putting textures over the top of people doesn't look good. It's something that I would avoid if I were you, until you're at a higher level and can start experimenting with that sort of thing. I think you're using too many images in your backgrounds that don't really mesh together that well and it makes your graphics look a bit unnatural. For now, why don't you try using one or two stock images in your backgrounds and then putting one or two people on top? Look in +this forum for some stock packs and download one. Try not to set your images to blending modes like lighten, darken, soft light, etc. because it's making your graphics look a bit harsh and lowering the quality of the images you're using.
I think the best way for you to improve would be to try and be a little bit more simple. There are a few things that you're doing in all your graphics (the things I've mentioned above) which is not very flattering and I think you'd be best off forgetting some of those techniques and starting just with some really simple things. Take a couple of stock images from a pack you download (don't forget to credit the artist!) and blend them together with a large, soft brush. Then put one or two people on top and blend them in. You don't need to do any extreme colouring, just keep things simple. I would also suggest using the critique area to post your graphics and get some feedback.
I hope this helped! Let me know if you ever want a hand with a particular graphic.