Most people use a sanitized piece of racking tubing or a cane that sits about an inch off the fermenting beer that leads into a sanitized covered container. It just blows off into the container.
Here is a video http://www.aleiens.com/video/top-cropping-yeast-from-a
I haven’t noticed a problem with using bottom cropped yeast, and its a lot easier to harvest this. Timing-wise I don’t generally re-use a yeast while the first beer is still brewing, if I was going to do that i’d just grow more starter or save a little and regrow a second batch. Once you store yeast for some weeks, I don’t think the fact that it is top-cropped (healthier and more active) makes a difference.
I’ve used a stainless ladle, but it takes some time to harvest a decent amount since the scoop is pretty small (to be able to fit through the carboy neck).
On the plus side, you’ll get one yeast cell per tiny ladle so you know how much yeast you are harvesting! You might even name them as you fish them out.