ASME Y14.5M-1994 covers this in paragraph 1.7.5. Notes and dimensions (non-baseline) should all be written to be "read from the bottom of the drawing". This means, if you hold the drawing in front of you on a table (for example), with the bottom edge nearest to you, then the dimensions must be readable from that direction. When ASME Y14.5M-1994 refers to "dimensions", it means all forms of dimensions not specifically excluded in the statement. So, this also applies to GD&T feature control frames.
Placement of the feature control frame is controlled by paragraph 3.5 of the ASME Y14.5-1994 standard. It may be below or attached to a leader-directed callout or dimension pertaining to the feature; running a leader from the frame to the feature (similar to leader notes), attaching a side or an end of the frame to an extension line from the feature, provided it is a plane surface; or attaching to the side or end of the frame to an extension line of a dimension line pertaining to the feature of size.