。
My technique is flawless.
Literal
My technique [to-に] oversight [topic-は] not-exist [feminine-わ].
テク is a casual abbreviation of テクニック ('technique'). 抜かりはない ('there are no oversights') uses 抜かり 'negligence, oversight' — a confident self-assessment. The feminine わ ending adds a self-assured, slightly playful tone. The whole sentence is a boast delivered with casual confidence.