"combine effortlessly" is correct and usable in written English.
It is a phrase used to indicate that two elements can be brought together easily without effort. For example, "The colors of the painting combined effortlessly to create a tranquil ambiance".
As a striking trait of his character, he showed fair-minded openness and diplomacy: Thomas could combine them effortlessly.
Germany's front four - Reus, Muller, Andre Schurrle and Mario Gotze - were irresistible at times, combining seemingly effortlessly and leaving the Scots defenders bamboozled by their movement.
They effortlessly combine personal and national histories with an exceptional kind of down-home formalism, all the while using available, often humble, fabrics.
Ranging across a variety of patterns and techniques and nearly two centuries, the examples here effortlessly combine personal and national histories with rigorous down-home formalism, all the while making brilliant use of available, often humble, fabrics.
Dubbed the First Lady of British Theatre, Thelma Holt is one of the country's most daring and visionary producers, a true maverick who can effortlessly combine the commercial prerogatives of the West End with the panoramic breadth of vision of some of the world's most progressive theatre artists.
The magic, the costumes, the attractions, the music, the frozen desserts, all effortlessly combine to achieve nearly universal appeal among young kids.
Grace's eye for fit and fabric was incredible; she knew how to effortlessly combine that "girl next door" charm with a hint of mystery.
The defining mark of Japanese electronica right now is the way its producers effortlessly combine the kitsch with the contemporary while borrowing elements from every genre.
Few painters managed so effortlessly to combine sentimentality and eroticism in a way that doesn't fill us with nausea.
She was able effortlessly to combine her fascination with science--both its history and its cutting edge of contemporary discovery--with an unembarrassed love of kitsch and a refined taste for the highest achievements in art, from which she learned freely and sought tirelessly to emulate.
