I don't feel quite like I should be giving critique, seeing as I haven't been doing much shooting lately, but a couple of your shots jumped out at me. You'll get your chance to return the favour soon, I'm sure!
The first lot:
Camellia - Well, to be honest, I find most flower pictures dull. Not that that stops me from taking them myself, of course... Anyway, I'd agree that this needs a tighter crop and shallower dof. If your lens allows it, it'd be neat to get right in so the flower fills the frame, and all you see are the concentric rings of petals, which I imagine is what drew you to the flower in the first place.
the light - Very cool! It seems a little flat, though - was it a grey day? It seems like all that glass ought to gleam. There are some distracting elements, I wonder if there is a different vantage point that would be less cluttered.
the lighthouse - You've already got some great help on this one. Nice composition, simple and clear, and conveys the height well.
great blue heron - The bird looks a tad out of focus. I know they're difficult to photograph, you never know when they're going to take off. It also looks like it's leaning on the shrub! A better angle to separate it from the background shrubbery would help, but you probably would have spooked it tramping around looking for better views. I've concluded that unless you have a big honkin' lens and/or stake out a known "bird spot" for hours, you just can't get really first-class photos of wary birds like these. Again, not that it stops me from trying...
Your other two:
boats in silhouette - Nice mood, soothing colour, I love the little bird on the roof! It's a bit busy, though, with all the aerials, strings of lights, and windows making "holes" in the silhouette. It might be improved by cropping off the sides to make it portrait orientation.
kayaks - Too much dof, too much background clutter. What caught your eye? The line of colourful kayaks, right? When you look at something in "real life", your brain edits out all the distractions - that's what "attention getting" is all about. But when you take a picture, you have to help the viewer see what you were seeing. Ever notice that when you look at a photo you've taken, you see stuff you didn't realise was there at the time you took it? That's because looking at a photo is different from looking at the real thing, on many levels. This is one of the hardest things to keep in my head when I'm shooting!
Back to your photo, though - you could crop out the car on the left, and that would help, but there's still too much dof. If you went back, or encountered something similar, try different angles to keep any bright objects in the background (like the truck cap visible over the kayaks) out of sight. Decide where to put the main focus - the dangling handle? the numbers on the bow? the abandoned water bottle? - and use a fairly wide aperture to isolate it. That'll put any visible background completely oof. Don't be afraid to fill the frame with your subject - unless you're interested in the context these kayaks are in, it doesn't matter if the building in the background, the trees, or whatever is even in the frame.
I've gone on about this one a little bit, but it illustrates something that I struggle with all the time - making your subject clear to your audience. You seem to have an eye for pattern (the flower petals, the light, the kayaks), so if you're taking a picture because you think the pattern's interesting, that's what
has to be the subject. Think of the people viewing your photos as being just a little stupid, so you sort of have to whack us over the head with it: "Hey, stoopid! Lookit the pattern! Forget it's a flower, look at the circles! Cool, eh?"
I also suspect that you didn't get your knees sandy taking the kayak photo.
Often the best angle on something involves getting into a really uncomfortable position and feeling a little silly. But don't worry, you're carrying a DSLR, people will assume you're a pro!
You're off to a good start, you'll get lots of help here.
By the way, what camera and lens(es) did you use?
Julie