Thanks for taking the time to introduce yourself. Getting sharp images is an interesting topic, I think that is worthy of doing an Inspiration Sheet (or possibly it should be called a technique sheet)
Not wanting to pre-empt that but three things to think about for sharpness.
1. Check what aperture you are using – your lenses will be at it’s sharpest f/8 – f/11.
2. Many ‘unsharp’ images can be blamed on not using a fast enough shutter speed. Rule of thumb is minimum shutter speed of 1/
3. Focusing and shooting technique. Try not to sway when shooting, and breath out as your press the shutter release
I look forward to seeing the results of you lead-in lines and beach images. Have a great time in Tenby.