What characterized the Guler–Kangra phase in terms of artistic practices?

Experimentation and improvisations

Answer:  Experimentation and improvisations
During the Guler–Kangra phase, artists indulged in experimentation and improvisations.

The most popular theme of Basohli painters was the Rasamanjari of Bhanu Datta. In 1694–95, Devida, a tarkhan (carpenter–painter), did a magnificent series for his patron Kirpal Pal. Bhagvata Purana and Ragamala were other popular themes. Artists also painted portraits of local kings with their consorts, courtiers, astrologers, mendicants, courtesans and others. While artist ateliers from Basohli, gradually, spread to other hill states, such as Chamba and Kullu, giving rise to local variations of the Basohli kalam. A new style of painting came in vogue during 1690s to 1730s, which was referred to as the Guler–Kangra phase. Artists during this period indulged in experimentation and improvisations that finally resulted and moulded into the Kangra style.