6 cards, each one idea: what it is, a worked example, and the trap to dodge.
Pick the layout
Decide row, single circle, or double row before placing anyone, and note the facing direction, it decides which way left and right point.
8 people around a table facing centre: number seats 1-8 clockwise, then place from there.
Trap: Facing the centre flips left and right versus facing outward. Draw an arrow to remember.
Anchor on the strongest clue
Begin with a fixed fact ('P sits at the head', 'Q is third from the left'). Everything else hangs off that anchor.
Immediate vs somewhere
'A is to the immediate left of B' places A right next to B. 'A is to the left of B' only means somewhere on that side, leave gaps to fill later.
Trap: Reading 'to the left' as 'immediate left' is the most common seating mistake.
Track gaps and counts
Use blanks for unknown seats and pencil in constraints. 'Exactly two people between X and Y' fixes distances quickly.
'Two persons sit between M and N' in a row of 6 leaves only a few placements to test.
Double rows and facing pairs
For two rows facing each other, a person in row 1 faces one specific person in row 2. A clue about one row often pins a seat in the other.
Verify against every clue
Before answering, re-read each clue and tick it against your final diagram. One unused or violated clue means the arrangement is wrong.