There are a few notes that I keep in mind about maintaining pressure, but I’ll preface it with this. Don’t be afraid to get reversed. You will want to bait them out, but don’t let the idea of eating a shoryu make you hesistant to do anything.
The goal of pressure, IMO, is to get your opponent to do something at a time they shouldn’t have. Reversal unsafely, or press a bad button. Secondary goals are pushing them into the corner where their options are further reduced increasing the chances they’ll do something foolish and setting up mixups which, if they land, will set up more offense and make an opponent steadily more desperate.
First safe generic pressure. c.lpxn. The most common true blockstring in the game, they can’t do anything to get out of this, so this is reversal safe. his generally means that you won’t deal any dmg either, but against reversal spammers this might be enough to get them to blow their load so you can punish. If people get used to the idea of so and so many jabs, then an offbeat throw or overhead will make them fidget a little. This is basic mixup. crouch teching[or better late teching], reversaling and just solid defense will blow through this, however - BUT first the idea is to get them to stop reversaling with proper baits and punishes. You can probably stop here if you just wanna be an online hero.
A slightly more seasoned player however, won’t bother with the idea of random reversals. They trust their defense enough that they feel they can get away freely and risklessly with good defense and then picking a good spot to BD/tech/tide it out/or if you’re getting feisty, reversal[which you should always be congnizent of - keep an eye on their habits!]. So your options have to branch out with theirs. One of the better ways is frame traps which are a string of moves that when strung together, cannot be hit by varying classes of normals[depending on the moves].
An example, makotos s.lp is i4[4 frame startup], her s.mp is +2 on block. If you get them to block a s.mp and then immediately do a s.lp there’s a mere 2 frame gap wherein the opponent can do anything. Except no normal moves[nor even throws!] are faster than 3f so if they hit a non invincible button. Guess what? You get a CH! This deters button mashers and restricts an opponents options to those dangerously punishable reversals, BD themselves into a corner, or having to continue to block[and maybe eat a mixup]! This also beats early crouch techs, although not late ones[which require bigger frame gaps and are thus more susceptible to many things.] Beating BDs is usually done through OSes, which are a set of commands that do varying things based on what happens in the game. Usually taking advantage of the fact that you can buffer chainable normals and jump in blockstun and such. I’ll let someone else explain I usually only use OS dashes and c.lp c.lp+hp stuff and this is getting long anyway. The idea that they’re cornering themselves is good enough for me.
[Quick note on this: This is what creates a ‘safe’ offense. doing something like c.lk xx hayate c. lk xx hayate is very UNSAFE to do since its -8. This means its flat out punishable, but even if they don’t if you continue to press buttons, ANY button they face splat into will hit you. Stay positive if you can!]
Final note about mentality, maintaining a coherent offense is all about staying one step ahead of your opponent while restricting their options. If you can do that you can win out of hand netting yourself an youtube worthy perfect. Generally this is impossible for non viper/AE yun/yang chars who had/have such overwhelming offensive[and safe!] pressure that they can really just lay it on so work on the other aspects of your game as well. Pressure can also be applied through proper application of footsies as well [mostly whiff punishing, but as just far ranging pokes] so look into that as well.