Rote learning gets a bad name but it works for me, not in isolation mind you, throw in other techniques to reinforce learning and hear words in context etc. When I have a LOT to memorise someone talking at me doesn't help me.
By this method I found my vocab was way ahead of others in my level(I am studying for the Spanish DELE, level A2). I also managed to skip the first two levels of the DELE course(A1.1 & A1.2) after taking a level test - this having never studied Spanish formally at any level.
By rote learning, I mean writing words out multiple times, big lists... and also, putting new words/short phrases I come across into an excel sheet and typing them out numerous times. After a few days the ones I dont remember I put them into a separate excel sheet and go over them until I know them.
I reinforce this by listening to Spanish podcasts, Duolingo and reading El Pais and MARCA. Pop any new words/short phrases into the excel sheet and you'll get back to them soon. I am now at nearly 4700 words/phrases in excel and have just started revising from 3000 on - I dont have 100% knowledge of the first 3000 yet, probably nearer 70-75% - but say one day you get 60 words wrong - pop them into a separate excel sheet. Practice them the next day you'll get maybe half of these words right. The next day try them again you'll get 60-70% of these right. Keep doing this and you'll eventually have mastered them all and you can move on. Make sure to take time every 7-10 days to go over all the words you have mastered just to reinforce further as not every one of these words is going to pop up when you read a couple of articles in a Spanish paper or listen to a podcast.