Estar a la venta to be for sale
Estar a la que salta to be alert/on the qui vive
Estar al día to be up to date
Estar al caer to be round the corner/arriving imminently
Estar al corriente to be informed
Estar al loro to be on the lookout
Estar al pie del cañón to be ready to support others and fulfill obligations and commitments
Estar como una cabra to be completely mad
Estar como unas castañuelas to be very happy
Estar como una moto to be high (from alcohol, drugs)
Estar como una rosa to be healthy
Estar como un tren to be very physically attractive
Estar como un toro to be physically vigorous/strong
Estar curado de espanto to be immune to something
Estar de baja to be on leave
Estar de bajón to be down
Estar de guasa to be joking/ kidding
Estar de lujo to feel amazing
Estar de moda to be fashionable
Estar de morros to be in a bad mood
Estar de racha to be in luck
Estar de suerte to be in luck
Estar de vacaciones to be on holiday
Estar de vicio to be really delicious (food)
Estar en la gloria to be on cloud nine/in heaven
Estar en las nubes to be daydreaming/distracted
Estar en el ajo to be in on something/in the loop
Estar en todo to be on top of everything/have everything under control
Estar entre la espada y la pared to be between a rock and a hard place
Estar hasta la coronilla to have had enough/ had it up to here
Estar hasta el moño to have had enough
Estar hasta en la sopa to be everywher
Estar para chuparse los dedos to be really delicious (food)/finger-licking good
Está que trina He/she is really upset
Está que muerde He/she is defensive
Estar sin blanca to be penniless
Estarle bien empleado to deserve a punishment/to serve him/her right
Estar por alguien to have a crush on somebody
Estar por las nubes to be very expensive for a period/to skyrocket (prices) of time
Estarse quieto to stand still
Estar al tanto (de algo) to be on the lookout