Preece et al. indicate that "there is no rigid border between conceptual design and physical design." They use prototypes for conceptual design (see section 8.3.4). For others, any prototype that shows layout and visual features must be specifying detailed design.
Rosson and Carroll divide this phase into Information Design and Interaction Design:
The two are inter-related and are often combined into one phase (such as with Preece et al).
Ben Shneiderman presents a list of general principles for creating detailed designs. Compare these principles to Jakob Nielsen's evaluation heuristics (see section 1.6.1).
Here is Shneiderman's list (detailed explanations can be found in section 8.4.1):
The display needs to be organized to help users find the content, commands and options that they need. Strategies for organizing content include:
Our text suggests organizing items so that fewer than 8 are grouped together (see figure 8.12).
Examples of widgets (also called user controls) are
We will discuss how these are used in various applications and if the user controls were appropriately chosen for the type of interaction. Here are some examples for discussion: