I think I’ve figured out a method that works best for me for doing strawberry crosses… I’ve been looking for freshly opened flowers with plump yellow anthers. I pluck these off with tweezers onto a dark and shiny surface. After about an hour or so, they’ll shrivel up and release a bunch of pollen. I pushed them around a little bit with the tip of the tweezers (or my finger) to knock some pollen loose and then just used my fingertip to apply the pollen to the central greenish-yellow part of a newly opened flower. In this case, I’ve been putting pollen of the “Clubhouse” strawberry (what we’ve started calling our white/yellow-fruited, everbearing, vesca type) onto flowers of ‘Red Wonder’ alpine strawberry. Any seedlings with runners should definitely be hybrids. All of the seedlings should be red-fruited and all should be everbearing.
The first image shows anthers freshly plucked from two flowers. The second image shows how even newly forming runners of "Clubhouse" are flowering.