After an initiation to meditation, a few responses are common.
The most common is to forget about it.
« The first steps felt good, useful, positive… Why continue? » Such a feeling might arise from feeling blasé: previous hopes were shattered by life, surely any improvement due to meditation will be short-lived. The feeling might also arise from thinking one has figured it all already, and there's no need for further practice. The feeling might finally arise from busy-ness: « I don't have time for this, it was nice but it's not a high priority for me to actually make time for it. It's not what I need right now. »
There's little answer to this attitude, except incentivising people to look at their life again: if it's great, if it's reliably pleasant, then there's little to change… but if it's not so reliable, if there's an underlying awareness that things might be temporary, that things might fall apart, if there's some awareness that no present success will protect you forever from ageing, sickness, disappointments and shattered dreams, then it would be useful to cultivate the tools that might help you manage the rougher times.
In order to train, people gradually push their limits. This is true of meditation, too. Just like nobody stands a chance in an Olympic race without prior training, nobody stands a chance of withstanding difficult times without prior training. Resilience is nurtured, not innate. Many people want to learn how to meditate in times of crisis, then forget about it as their situation normalises, than want once again to learn how to meditate when the next crisis arises: it doesn't work this way. While (calm-abiding) meditation might indeed help during a crisis, it is only treating the symptoms. If you want to treat the causes, the practice starts prior to the crisis… so that the crisis doesn't arise in the first place, or at least does so in a milder form. Prevention might not give the adrenaline or dopamine highs, it may appear ‘boring’ to the addicted brain, but it's only blind ignorance that leads to thinking that hormonal ups and downs are worth the grief that accompanies them: there's bliss too in riding storms without experiencing major lows, anxiety, anguish…
Another common response, after acknowledging the benefits, is to want to meditate more, in order to reap more benefits, faster.
This can be a dual-edged sword.
First, “spiritual materialism” doesn't work. Craving for specific benefits (usually those experienced first) blinds people from other benefits (more subtle, easier to miss, but just as important —if not more— in the long run). It is one of the key lessons when monitoring your own attention and awareness to notice how focus comes with blindness, and openness comes with a lesser ability to impose one's ‘own’, preconceived agenda. To meditate more might be useful, but it is unlikely to yield more of the same results: the other results may well be worth the effort, but it is important not to set misguided anticipations, or unnecessary disappointments will be created and such a form of self-sabotage lessens your motivation!
Second, one goal of the meditative practice is to cultivate a state of awareness “all the time”: a deep and wide discernment of what the situation at hand is, moment after moment, the renunciation of conditioned responses, the disengagement from the automatic pilot, the disenchantment from prejudices… This “all the time” could be seen as a matter of ‘more’, but in fact it is a question of ‘less’: less preparation, less ritual, less « I meditate only when the conditions are supportive, » less preliminaries. The truth is that it's impossible to maintain such a state of awareness permanently, we're too conditioned (physically, biologically, psychologically) for that, but we can perpetually recreate it, every time we notice that we lost it! And the closer to “all the time” we can get is by becoming able to re-attain meditative awareness in less than a breath!
So if you want to meditate more, it's probably achievable by meditating more often, rather than by meditating for longer periods of time. Longer periods of time are harder to place in a calendar, they're more easily disrupted by life events, they're bigger targets of criticism by others who opine that « surely you have better things to do »: longer periods often mean less training, in actual terms (unless you're extraordinarily disciplined or in a very supportive environment —e.g. having weekly calls with me)! To train more often is really what it's about: becoming able to use the meditative approach in any situation, at any time (including in the midst of a crisis). You can play with this, and you might of course combine longer meditations with more frequent meditations. The key point, here, is not to assume that ‘longer’ equates ‘better’. ‘Longer’ might play a training role: it might be supportive or useful (e.g. to break some bad habits), but it's not the goal.
In Buddhist monastery, the bell is often called the “mindfulness bell”. It does not only create a rhythm for participants to synchronise their actions, to switch between activities, etc. It also acts as a reminder to be present (to the reality you're currently in, and to the lessons that may apply accordingly).
The first application is at the end of meditation sessions: when the bell rings, instead of the beginner's joy of being freed from the artificial constraints of the posture, the experienced practitioner will use it to be present to the sound, to check one's posture, to note any emotion (joy of recovering freedom of movement, or sadness of losing the calm?), etc. The bell does not free the practitioner from paying attention, on the contrary it calls him/her to pay attention, to bring his/her mind back from its unexamined wandering!
As you rightly guessed, the bell itself doesn't impose anything though. “How one relates to the bell” is what unfolds in various consequences, notably in dullness or in alertness. And how you relate to the bell is a choice. To make an informed choice about that, you need to look at your life and discern what might support and what might hinder your flourishing.
Once you understand this, and combine this “mindfulness bell” with the “meditate more often rather than for longer periods of time”, you might pick a stimulus which is reasonably frequent in your life and resolve to relate to the stimulus differently, resolve to use the stimulus as a “pay attention” wake-up call.
In the office, the phone ringing, or any signal notifying you of new emails, might thus be taken as an opportunity to reconnect with your breath, with your posture, to observe your state of mind and how it might carry you away if you don't recentre on who you want to be, etc. You only need “one breath” before picking up the phone, or checking on messages, to reconnect with who you want to be, to not let what just happened to dictate how you will respond to whatever comes next, out of momentum and inertia… Not twenty minutes of seating: one breath!
Of course, “noticing a frustration/aversion” can be a great mindfulness bell… so being called for yet another boring meeting? Mindfulness bell! Being asked to make a presentation, or any other anxiety-generating ‘assignment’? Mindfulness bell! End of a task (how often those who wish they didn't have to sit an exam, also wish they had more time to complete it)? End of a break? Beginning of a task? Having to walk? Having to take or wait for public transport? Mindfulness bells!
When meditation takes no time at all, barely a breath, then you can fill your day with it!