Most of the illustrations below are from the story of Samson and Delilah (Judges 16). While I could certainly believe that the artists would be depicting Delilah with whatever ad hoc cutting tool a woman might have been handy – notice their similarity to shears for cutting fabric or shearing sheep – it seems that these spring scissors may have been a standard implement for cutting one's hair, judging by their presence in scenes in which a novice's hair is cut. Knives appear in a few of these illustrations, too. Pivoted scissors appear more frequently in the 16th and 17th century illustrations.

(For more on the subject of the history of scissors, see Medieval Finds from Excavations in London: Knives and Scabbards or Findings: The Material Culture of Needlework and Sewing.)

Some additional links on medieval & Renaissance hairstyles, including hair care recipes.

• Samson and Delilah, The Maciejowski Bible (PML M.638, fol. 15r), c. 1250
• Samson and Delilah, the Psalter of St. Louis (BNF Latin 10525, fol. 61v), c. 1270
• An abbess cuts the hair of a novice, Le Livre de Lancelot del Lac (British Library Add. 10293, fol. 261), c. 1316
• Samson and Delilah (fol. 82v) and preparations for the marriage of a prisoner of war (fol. 226v), Concordantiae caritatis (SBL 151), c. 1349-1351
• Samson and Delilah, Bible Historiale (MMW 10 B 23, fol. 123r), 1372
Unto his lemman Dalida he tolde
That in hise heeres al his strengthe lay,
And falsly to hise fooman she hym solde;
And slepynge in hir barme upon a day
She made to clippe or shere hise heres away,
And made hise foomen al this craft espyn.

The Monk's Tale (ll. 175-180)
in The Canterbury Tales

• Samson and Delilah, Bible Historiale (WLB 2° 6, fol. 109v), c. 1380-1390
• Samson and Delilah, Bible Historiale (PML M.394, fol. 112r), first quarter of the 15th century
• Samson and Delilah (fol. 152v) and the prophet Ezekiel cuts off his hair and beard and burns it (fol. 241r), Bible Historiale (KB 78 D 38 I, fol. 152v), c. 1430
• Samson and Delilah, an illustrated bible (ÖNB 2774, fol. 106r), 1448
• The Barber from a deck of cards for Hofämterspiel, c. 1450
• Desco da parto with the Triumph of Love by Apollonio di Giovanni, c. 1460-1470
• St. Francis accepts St. Claire as a novice, c. 1465-1475
• Confirmation from the Seven Sacraments, a tapestry woven c. 1470-1475
• Delilah cuts Samson's hair, Des cas des nobles hommes et femmes maleureux (British Library Royal 14 E. V, fol. 54v), 1470-1483
• Samson and Delilah by Andrea Mantegna, c. 1495
• Samson and Delilah by Albrecht Altdorfer, 1506
• Samson and Delilah by Lucas van Leyden, 1508
• Samson and Delilah from a stained glass roundel, c. 1510
• The Barber by Lucas van Leyden, 1524
• Samson and Delilah by Lucas Cranach the Elder, 1529
• Samson and Delilah by Lucas Cranach the Elder
• Samson and Delilah by Lucas Cranach the Younger, 1537
• Samson and Delilah, 16th century
• Samson and Delilah by Gerrit van Honthorst, c. 1615