ق is articulated with the back/root of the tongue rising toward the soft palate. It is the rearmost of the tongue articulation points.
In words such as قَلْب and خَلَقَ, qaf must retain its distinct identity. Its point is slightly further back than that of ك; everyday pronunciation habits must not erase that difference.
Practise أَقْ and أَكْ alternately, listening for the deeper contact of qaf and the relatively forward contact of kaf.