The handlebars should be at your waist level or slightly lower. In addition, the tandem models are generally more stable and fold more compactly. Never hang purses or diaper bags on the handles of a stroller. A baby could get tangled in the straps and be strangled. All toys should be checked frequently for loose or broken parts.
Some toys have small parts that can cause choking, so heed all warnings on a toy's packaging.
Make sure the toy is unbreakable and has no sharp edges. It should be large enough that it can't be swallowed or lodged in the throat. It shouldn't have any small parts such as eyes, wheels, or buttons that can be pulled loose, and it should be strong enough to withstand chewing. There should be no parts that could become pinch points for small fingers. There shouldn't be strings longer than 7 inches.