Not so much a tip, more of a must do! ..especially if your a beginner like me, this has saved me more time and hard work than anything else.
If you do this when you first open a page in BV web builder it will save you a lot of time consumming work later on.
Step1. Open up page in BV web builder
Step2. Go to Layout at the top of the page next to tools.
Step3. Scroll down to guide settings.
Step4. Tick box that says "show guide borders" theres also a grid, I use both.
Step5. Set page width to 800 x600 tho the (600) length isnt that important.
Step6. Click ok... your done
Now when you look at your page you will see a dotted line around the area you need to work within.
The dotted line at the bottom isnt so important as its better to have to scroll up and down rather than from side to side (sideways scroll)
The dotted line to the right of your page is the one to look out for, keep all your work, Images, text, shapes, etc to the left or just on the dotted line. and you will never have a sidways scroll and always check your page width before saving
Hope this helps you as it has helped me