Well you can add physical ram to a phone, you can flash a kernel or bootloader that reallocates some ram, but this is device specific and often takes some very intelligent programmers to make this happen.
The other way is to use virtual ram in the form of a swap partition, this will use sdcard or internal data or whatever partition you make work, function as ram, but it is slower than real ram and depending on how you use your device may make it slower altogether. I believe this is the method of increasing ram that you did, the easiest way to see if it worked is to open a terminal emulator and type
The final way is with compcache or zram, both squash ram and has a similar caveat to using swap as it may make things worse.
A few Google or xda searches should explain this a bit more than I have
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